Chem/Phys Flashcards
(691 cards)
1
Q
How is a scalar calculated from the product of two vectors?
A
Dot product ( [A] x [B] x cos theta )
2
Q
How is a vector calculated from the product of two vectors?
A
Cross product ( [A] x [B] x sin theta )
3
Q
When calculating frictional forces, how is directionality assigned?
A
The direction of friction always opposes movement, so once the instantaneous velocity/net force vector is known, the frictional force must be in the opposite direction
4
Q
When no force is being applied, the velocity must be:
A
Constant (no acceleration)
5
Q
How do the forces acting in free fall and projectile motion differ?
A
Gravity is the only force present in both free fall and projectile motion
6
Q
What is the difference between rotational equilbrium and translational equilibrium?
A
Rotational equilibrium occurs in the absence of net torque acting on an object, translational equilibrium occurs in the absence of any net forces acting on an object
7
Q
What are conservative forces, and how do they impact mechanical energy? Does the path taken matter? What are some examples?
A
Conservative forces = total mechanical energy does not change, path taken does not matter, examples = gravity and electrostatic forces
8
Q
What are nonconservative forces, and how do they impact mechanical energy? Does the path taken matter? What are some examples?
A
Nonconservative forces = total mechanical energy does change, path taken does matter, examples = friction and air resistance
9
Q
What are three ways of calculating work?
A
W = Fd cos theta, W = P DeltaV, W = DeltaK
10
Q
As the length of an inclined plane increases, what happens to the force required to move an object the same displacement?
A
The force required decreases
11
Q
What accounts for the difference between work input and work output in a system that operates at less than 100% efficiency?
A
Decrease in work output is due to nonconservative or external forces that generate/dissipate energy
12
Q
What are the six simple machines?
A
Inclined plane, wedge, wheel and axle, lever, pulley, and screw
13
Q
A 1000 kg rocket ship, traveling at 100 m/s, is acted upon by an average force of 20 kN applied in the direction of its motion for 8 seconds. What is the change in velocity of the rocket?
A
F = ma -> a = F/m -> a ( or change in V) = (20 x 10^3) (8) / (1000 kg) = 160 m/s
14
Q
A car is traveling at 40 km/hr and the driver puts on the brakes, bringing the car to rest in a time of 6 seconds. What is the magnitude of the average acceleration of the car?
A
USE EQUATION A = delta V/t -> (40 km/hr) (600 seconds/1 hr) = 24,000 km/hr^2
15
Q
If an elevator is moving upward at speed of 5 m/s after an initial period of acceleration, what is the relationship between the maximum tension of the cable and the maximum weight of the elevator?
A
The tension is greater than the maximum weight
16
Q
If one object is thrown vertically downward at 5 m/s and another object is thrown vertically upward with a speed of 10 m/s, which object undergoes a greater change in speed in 2 seconds?
A
The first object has a greater change in speed
17
Q
A firefighter jumps horizontally from a burning building with an initial speed of 1.5 m/s. At what time is the angle between his velocity and acceleration vectors the greatest?
A
The instant he jumps
18
Q
A 10 kg wagon rests on a frictionless inclined plane. The plane makes an angle of 30 degrees with the horizontal. Approximately how large is the force required to keep the wagon from sliding down the plane?
A
mg sin theta = (10) (9.8) sin 30 = 49 N
19
Q
A 20 kg wagon is released from rest from the top of a 15 m long lane, which is angled at 30 degrees with the horizontal. Assuming that there is friction between the ramp and the wagon, how is this frictional force affected if the angle of the incline is increased?
A
As theta increases, cos theta decreases which decreases the frictional and normal forces)
20
Q
A BASE jumper runs off a cliff with a speed of 3 m/s. Which of the following is closest to his speed after 0.5 seconds?
A
V = V0 + at -> V = (-9.8) (0.5) = -4.9 -> Pythagorean theorem (sqrt ((3)^2 + (-4.9)^2)) = sqrt (34) ~ 6 m/s
21
Q
A 2 kg rock is shot up vertically at the same time that a 0.5 kg ball is projected horizontally. If both start from the same height:
A
The ball will reach the ground first
22
Q
What is a true statement about movement on a plane with friction?
A
More force is needed to accelerate a stationary object than an identical moving object
23
Q
What is the value of tension in each rope in a pulley system if the mass of the object is 10 kg and the object is accelerating upwards at 2 m/s^2?
A
2T - mg = ma -> 2T = m (g + a) -> T = 10 (10+2) / 2 = 60 N
24
Q
A massless spring initially compressed by a displacement of two centimeters is now compressed by four centimeters. How has the potential energy of this system changed?
A
The potential energy has quadrupled (elastic potential energy = 1/2 kx ^2, 2^2 = 4)
25
A parachutist jumps from a plane. Beginning at the point when she reaches terminal velocity (constant velocity during freefall), what are some true statements?
The jumper is in translational equilibrium, and there is an equal amount of work being done by gravity and air resistance
26
A consumer is comparing two new cars. Car A exerts 250 horsepower, while Car B exerts 300 horsepower. The consumer is most concerned about the peak velocity that the car can reach. If nonconservative forces can be ignored, which of the following statements is true?
Car A and Car B both have unlimited velocities
27
What is the transition state theory?
Forming a high-energy activated complex that can then proceed forward or backward, forming the products or reverting to the reactants
28
What is the collision theory?
The energy and orientation of reactants, and considers each potential reaction to be "all-or-nothing"
29
In a certain equilibrium process, the activation energy of the forward reaction is greater than the activation energy of the reverse reaction. This reaction is:
Nonspontaneous
30
What is the equation for Q?
Q = concentration of products / concentration of reactants
31
If pH is increased in a chemical reaction:
The reaction shifts towards H+ because the concentration of H+ decreases
32
What are kinetic products?
Kinetic products are favored at low temperatures with low heat transfer
33
What are thermodynamic products?
Thermodynamic products are favored at high temperatures with high heat transfer
34
On a reaction coordinate diagram, how do kinetic pathways compare to thermodynamic pathways?
Kinetic pathways require a smaller gain in free energy to reach the transition state, have a higher free energy of the products, and a smaller difference in free energy between the transition state and the products
35
A reaction if found to stop just before all reactants are converted to products. Which of the following could be true about this reaction?
The reaction is reversible, and the forward rate is equal to the reverse rate
36
What is the value of K that is used for gases?
Kp
37
What are a few statements about equilibrium reactions?
As the concentration of the products increases, the concentrations of reactants decreases; the equilibrium constant is altered by changes in temperature
38
What is the maximum distance that two objects can be from one another and still adhere to the zeroth law of thermodynamics?
There is no maximum distance
39
What is the most accurate measurement method for temperature?
There is none; Celsius and Kelvin are equally as good
40
What are some examples of state functions?
Pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, entropy
41
What are some examples of path functions?
Heat and work
42
What is the relationship between internal energy, work, and heat?
Internal energy = heat - work
43
What is conduction?
Heat exchange by direct molecular interactions
44
What is convection?
Heat exchange by fluid movement
45
What is radiation?
Heat exchange by electromagnetic waves, and does not depend on matter
46
Where is work on a P-V graph?
The area under the curve
47
What is entropy in macroscopic and statistical terms?
Macroscopic = tendency toward disorder, statistical = measure of the spontaneous dispersal of energy at a specific temperature
48
What is the relationship between the entropy of a system and its surroundings for any thermodynamic process?
Will never decrease (will either remain constant or increase)
49
What is the relationship between Celsius and Kelvin?
The kelvin unit and Celsius degree are the same size
50
What occurs when heat is transferred from the Sun to the Earth?
Radiation
51
What occurs when a metal spoon heats up when placed in a pot of hot soup?
Conduction
52
What occurs when a rising plume of smoke emerges from a fire?
Convection
53
A 20 m steel rod at 10 degrees C is dangling from the edge of a building and is 2.5 cm from the ground. If the rod is heated to 110 degrees Celsius, will the rod touch th ground?
No because it expands by 2.2 cm (delta L = alpha * L * delta T) - beta = 3*alpha
54
What is the final temperature of a 3 kg wrought iron fireplace tool that is left in front of an electric heater, absorbing heat energy at a rate of 100 W for 10 minutes? Assume the pendant is initially at 20 degrees C, and that the specific heat of wrought iron is 500 J / kg * K - what equations do you use?
E = P*T and q = mcdeltaT
55
How much heat is required to completely melt 500 g gold earrings, given that their initial temperature is 25 degrees C? (MP of gold is 1064 degrees C, heat of fusion = 6.37 x 10^4 J/kg, specific heat = 126 J / kg*k) - which equations do you use?
E = P * t , q = mcdeltaT
56
In an adiabatic compression process, the internal energy of the gas:
Increases because the work done on the gas is positive
57
The entropy of a system can:
Decrease when the entropy of the surroundings increases by at least as much (no net decrease)
58
If two substances have the same freezing and boiling points, and solid samples of both substances are heated in the exact same way, substance A boils before substance B. Why?
Substance B has a higher specific heat, heat of vaporization, and heat of fusion
59
In experiment A, a student mixes ink with water and notices that the two liquids mix evenly. In experiment B, the student mixes oil with water; in this case, the liquids separate into two different layers. The entropy change is:
Positive in experiment A and zero in experiment B
60
What is gauge pressure?
Gauge pressure is equal to the pressure exerted by a column of fluid plus the ambient pressure above the fluid, minus atmospheric pressure. When atmospheric pressure is the only pressure above the fluid column, then gauge pressure equals the fluid pressure
61
How are weight and density related?
Weight is density * volume and acceleration due to gravity
62
To which side of a hydraulic lift would the operator usually apply a force - the side with the larger or smaller cross-sectional area?
Smaller cross-sectional area because pressure will be the same on both sides of the lift, so a smaller force can be applied on the smaller surface area to generate the desired pressure
63
What is dynamic pressure?
The pressure associated with flow, and is represented by 1/2 pv^2
64
What is static pressure?
The pressure associated with position, is sacrificed for dynamic pressure during flow
65
What is a pilot tube?
A device that measures static pressure during flow to calculate speed
66
What is viscosity?
A measure of the resistance of a liquid to flow
67
What is laminar flow?
Flow in which there are no eddies and in which streamlines are roughly parallel to each other
68
What is turbulence?
The presence of backflow or current eddies
69
What is the continuity equation?
Describes the relationship of flow and cross-sectional area in a tube (A1V1 = A2V2)
70
What is Bernoulli's equation?
States that 1) points 1 and 2 lie on a streamline, 2) the fluid has constant density, 3) the flow is steady, and 4) there is no friction; (p1 (pressure energy) + 1/2pv1^2 (kinetic energy) + pgh1 (potential energy) = p2 + 1/2pv2^2 + pgh2)
71
What is the Venturi effect?
Q = AV; flow rate stays the same and surface area decreases = velocity must increase
72
What equation can be applied to the circulatory system?
Poiseulle's Law (Q = pi * pressure * r^4 / 8 * viscosity * length of tubing)
73
What happens to air as it exits the body?
Resistance increases
74
How does the flow in the venae cavae relate to flow in the main pulmonary artery?
The flow should be equal, but the flow is a little less in the venae cavae because some of the blood entering the heart is from cardiac circulation
75
If the density of object A is one third of object B, and the gauge pressure of object A is 3 atm, what is the gauge pressure of object B?
3 atm (gauge pressure depends on density of FLUID) - gauge pressure (of fluid) = total pressure - atmospheric pressure
76
An anchor made of iron weighs 833 N on the deck of the ship. If the anchor is now suspended in seawater by a massless chain, what is the tension in the chain?
Tension = Fg - Fbuoy = 833 N - 109 N = 724 N
77
Water flows from a pipe of diameter 0.15 m into one of diameter 0.2 m. If the speed in the 0.15 m pipe is 8 m/s, what is the speed in the 0.2 m pipe? - what equation should you use?
V1A1 = V2A2 -> 8 (0.15/0.20) ^ 2 = 4.5 m/s
78
If water is allowed to flow through the pipe to the right, in which of the vertical pipes will the water level be lowest?
Pipe 2 (smallest horizontal diameter)
79
Which of the following data sets is sufficient to determine the linear speed through an area of a rigid pipe?
The radius, pressure gradient, viscosity, and length of the pipe (Poiseuille's Law - pi*p*r^4 / 8*viscosity*length of tubing)
80
A large cylinder is filled with equal volumes of two immiscible fluids. A balloon is submerged in the first fluid; the gauge pressure in the balloon at the deepst point in the first fluid is found to be 3 atm. Next, the balloon is lowered all the way to the bottom of the second fluid, where the hydrostatic pressure in the balloon reads 8 atm. What is the ratio of the gauge pressure accounted for by the first fluid to the gauge pressure accounted for by the second fluid?
3:04
81
What is the relationship between Bernoulli's equation and flight?
The speed of airflow is greater over the curved top of the wing, resulting in less pressure on the top of the wing and the production of a net upward force on the wing, in turn resulting in flight
82
What are the values of isothermal, adiabatic, isobaric, and isovolumetric?
Isothermal = delta U = 0, Q = W; Adiabatic = Q = 0, delta U = -W; Isobaric = line appears flat in a P-V graph; Isovolumetric = W = 0, delta U = Q
83
What is the triple point?
The specific combination of temperature and pressure at which all three phases are in equilibrium
84
What is the critical point?
The temperature and pressure above which the liquid and gas phases are indistinguishable and the heat of vaporization is zero
85
What is heat capacity?
Specific heat * mass
86
What is a coffee cup calorimeter?
Constant pressure calorimeter - As the reaction proceeds, the temperature of the contents is measured to determine the heat of the reaction
87
What is a bomb calorimeter?
Heats of certain reactions (like combustion) can be measured indirectly by assessing temperature change in a water bath around the reaction vessel (CONSTANT VOLUME CALORIMETER)
88
What is a calorie?
1 cal/ g*K
89
What is the difference between endothermic and exothermic reactions?
Endothermic reactions involve an increase in heat content of a system from the surroundings, while exothermic reactions involve a release of heat content from a system
90
Can entropy of the universe decrease?
No
91
What is sublimation?
Solid -> gas
92
What is deposition?
Gas -> solid
93
What is the equation for Gibbs free energy?
Delta G = Delta H - T*Delta S
94
What is the shape of adiabatic on a P-V graph?
Hyperbolic
95
What is the equation for change in Gibbs free energy?
Delta G = Delta Gprime + RTlnQ
96
Explosions are necessarily characterized by:
Negative Delta G
97
Name some characteristics that make the gas phase unique.
Gases are compressible fluids with rapid molecular motion, large intermolecular distances, and weak intermolecular forces
98
How would atmospheric pressure change by altitude?
Atmospheric pressure is lower at higher altitude, hydrostatic and atmospheric pressures are present at lower altitudes
99
What is STP?
T = 273 K (0 degrees C), P = 1 atm
100
What are standard conditions?
T = 298 K (25 degrees C), P = 1 atm, concentration = 1 M
101
How do I find density from the PV = nRT equation?
Density = m/v = PM/RT
102
How can the concentration of carbon dioxide in sodas or other carbonated beverages be so much higher than that of atmospheric carbon dioxide?
High pressures of carbon dioxide gas are forced on top of the liquid in sodas, increasing its concentration in the liquid
103
What are some assumptions of the kinetic molecular theory?
Negligible volume of gas particles, no intermolecular forces, random motion, elastic collisions, proportionality between absolute temperature and energy
104
What is the root mean square speed equation?
Urms = sqrt (3RT/M)
105
What equation should you use to determine average speed?
r1/r2 = sqrt (M2/M1)
106
Why would you smell a rotten egg odor (hydrogen sulfide) before wintergreen (methyl salicylate)?
Since they are at the same temperature, the gases that is the lightest travels the fastest
107
In what ways do real gases differ from ideal gases?
Real gases deviate from ideal gases at high pressure (low volume) and low temperature
108
Which gas will exert a higher pressure under the same, nonideal conditions: methane or chrloromethane?
The real pressure of methane will be higher (closer to ideal), value of a is smaller for methane
109
If methane and isobutane are placed in the same size container under the same conditions, which will exert the higher pressure?
Since the b value is higher for isobutane, it would make the "v-nb" value smaller, so the pressure for isobutane would have to increase
110
What is ideal gas behavior?
High temperature and low pressure
111
Ideal gases have:
Particles with no attractive forces between them
112
An 8.00 g sample of NH4NO3 is placed into an evacuated 10 L flask and heated to 227 degrees C. After the NH4NO3 completely decomposes, what is the approximate pressure in the flask?
1.23 atm - write out a balanced equation, convert to moles
113
How would speed of helium and bromine compare to each other on a graph?
Helium has a smaller molar mass than bromine, greater overall average speed
114
The gaseous state of matter is characterized by:
Gases are compressible and assume the volume of their containers
115
When placed one meter apart from each other, which will experience greater acceleration: one coulomb of electrons or one coulomb of protons?
One coulomb of electrons (same charge, less mass)
116
What are some examples of insulators and conductors?
Insulators = hair, glass, distilled water; Conductors = blood, copper, iron, sulfuric acid
117
How do distance and charge relate to electrostatic force?
Directly related to each charge, related to the distance by an inverse square relationship
118
How do distance and charge relate to electric field?
Unrelated to test charge, related to distance by an inverse square relationship
119
How does a change in electric potential energy from -4 J to -7 J reflect on the stability of the system?
More stable
120
Compare the relationship between electric potential energy and Coulomb's law to the relationship between gravitational potential energy and the universal law of gravitation
Coulomb's law (kq1q2 / r^2) = EPE (kq1q2 / r)* distance, Universal law of gravitation (Gm1m2/r^2) = GPE (mgh) * distance
121
By what factor would electric potential energy change if the magnitude of both charges were doubled and the distance between them was halved?
The EPE would be multiplied by a factor of 8
122
What is the difference between electric potential and voltage?
Electric potential = the ratio of a charge's electric potential energy to the magnitude of the charge itself, Voltage = a measure of the change in electric potential between two point
123
How will a charge that is placed at a point of zero electric potential move relative to a source charge?
Will move in a way to minimize its potential energy, the charge may or may not move
124
What are the units of electric potential energy / electric potential?
EPE = Joules, EP / PD (voltage) = Volts
125
What are equipotential lines?
The sets of points within space at which the potential difference between any two points is zero, there is no voltage between two points on an equipotential line
126
What is an electric dipole?
The separation of charge within a molecule such that there is a permanent or temporary region of equal and opposite charges at a particular distance
127
Why is the electric potential at points along the perpendicular bisector of a dipole zero?
The perpendicular bisector of an electric dipole is an equipotential plane that is perpendicular to the axis of the dipole. As such, the equation V = kqd / r^2 cos theta is necessarily equal to 0 because cos 90 = 0
128
What is the behavior of an electric dipole when exposed to an external electric field?
A dipole will rotate within an external electric field such that its dipole moment aligns with the field
129
How do you create an electric field?
Charge
130
How do you create a magnetic field?
Charge that is moving
131
How do you create a magnetic force?
An external electric field acting on a charge moving any direction except parallel or antiparallel to the external field
132
Two parallel conducting plates are separated by a distance d. One plate carries a chare +Q and the other carries a charge -Q. The voltage between the plates is 12 V. If a +2uC charge is released from rest at the positive plate, how much kinetic energy does it have when it reaches the negative plate?
W = delta U = Q * delta V = (2 x 10^-6 C) (-12 V) = -2.4 x 10^-5 J
133
If the magnetic field a distance r away from a current-carrying wire is 10T, what will the net magnetic field at r if another wire is placed a distance of 2r from the original wire (with r in the middle) and has a current twice as strong flowing in the opposite direction?
30 T
134
Given an electric dipole, the electric potential is zero:
Anywhere on the perpendicular bisector of the dipole axis and at infinity
135
A certain 9 V battery is used as a power source to move a 2 C charge. How much work is done by the battery?
Delta V = Delta U / q = W / q (9 V * 2 C = 18 J)
136
A proton and an alpha particle repel each other with a force of F while they are 20 nm apart. If each particle combines with three electrons, what is the magnitude of the new force between them?
Force would still be F
137
A moving negative charge placed in an external magnetic field circulates counterclockwise in the plane of the paper. In which direction is the magnetic field pointing?
Out of the page
138
A dipole is placed in an electric field and is allowed to come to equilibrium. How would the dipole react if the direction of the electric field is suddenly reversed?
It experiences no rotational or linear movement
139
What is current?
The movement of positive charge through a conductive material over time, unit = amperes
140
What is voltage?
A potential difference between two points, unit = Volts
141
What is electromotive force (emf)?
The potential difference of the voltage source for a circuit, unit = Volts
142
What is conductivity?
The reciprocal of resistance, a measure of the permissiveness to current flow, unit = siemens
143
Which likely has a higher conductivity: 1 M glucose or 0.25 M NaCl?
0.25 M NaCl (is a salt, will increase the ion content of water)
144
In a circuit, the number of electrons entering a point and leaving that point are the same
True (Kirchhoff's Junction Rule)
145
The sum of the voltage sources in a circuit is equal to the sum of the voltage drops in that circuit
FALSE
146
How does adding or removing a resistor change the total resistance of a circuit with resistors in series? In parallel?
Adding a resistors to resistors in series increases the resistance, decreases the resistance for resistors in parallel
147
How does power relate to current, voltage, and resistance?
P = IV = I^2R = V^2/R
148
A circuit is set up with three resistors. What proportion of the total current will travel through each resistor?
All of the circuit will go through the first resistor
149
After a voltage source has been taken away, how does the capacitor behave?
The capacitor discharges, providing a current in the opposite direction of the initial current
150
How does a dielectric material impact capacitance? Voltage? Charge?
Will always increase capacitance, will decrease voltage and keep charge constant if isolated, will keep voltage constant and increase charge if part of a circuit
151
How does adding or removing a capacitor change the total capacitance of a circuit with capacitors in series? In parallel?
Adding a capacitor in series decreases the total capacitance, removing one in series increases the total capacitance (opposite for parallel)
152
What physical qualities contribute to the capacitance of a capacitor?
Dielectric constant, distance, surface area
153
What is an ammeter?
Measures current, placed in series with point of interest, ideally zero resistance
154
What is a voltmeter?
Measures potential difference (voltage), placed parallel with circuit element of interest, ideally infinite resistance
155
What is an ohmmeter?
Measures resistance, placed at two points in series with circuit element of interest, ideally zero resistance
156
True or False: a voltmeter and an ammeter should not be placed in the same circuit
False, they can be used together
157
A voltaic cell provides a current of 0.5 A when in a circuit with a 3 ohms resistor. If the internal resistance of the cell is 0.1 ohms, what is the voltage across the terminals of the battery when there is no current flowing?
V = IR -> (0.5 A)(3 ohms) = 1.5 V; e = V + ir = 1.5 V + (0.5 A)(0.1 ohm) = 1.55 V
158
A transformer is a device that takes an input voltage and produces an output voltage that can either be larger or smaller than the input voltage, depending on the transformer design. Although the voltage is changed by the transformer, energy is not, so the input power equals the output power. A particular transporter produces an output voltage that is 300% of the input voltage. What is the ratio of the output current to the input current?
1:3 -> IoutVout = IinVin
159
How many moles of electrons pass through a circuit containing 100 V battery and a 2 ohm resistor over a period of 10 seconds? -> what equations should you use?
V = IR and I = Q/delta T -> Q = V * Delta T / R = (100 V)(10 s) / 2 ohms = 500 c; 500 C / 10^5 = 5 x 10^ -3
160
If the area of a capacitor's plates is doubled whiel the distance between them is halved, how will the final capacitance compare to the original capacitance?
4x the original capacitance
161
The energy stores in a fully charged capacitor is given by U = 1/2 CV ^2. In a typical cardiac defibrillator, a capacitor charged to 7500 V has a stored energy of 400 J. Based on this information, what is the charge on the capacitor in the cardiac defibrillator?
U = 1/2 CV^2 = 1/2 (Q/V) V^2 = QV/2 ; Q = 2U/V = 2(400 J)/7500 V = 0.1 C
162
Which of the following will most likely increase the electric field between the plates of a parallel plate capacitor?
Adding an extra battery to the system
163
Which of the following best characterizes ideal voltmeters and ammeters?
Ideal voltmeters have infinite resistance, and ideal ammeters have no resistance
164
What is wave speed?
The rate at which a wave transmits the energy or matter it is carrying (product of frequency and wavelength)
165
What is frequency?
A measure of how often a waveform passes a given point in space (Hz)
166
What is angular frequency?
The same as frequency, but is measured in radians per second
167
What is period?
The time necessary to complete a wave cycle
168
What is equilibrium position?
The point with zero displacement in an oscillating system
169
What is amplitude?
The maximal displacement of a wave from the equilibrium position
170
What is a traveling wave?
Have nodes and antinodes that move with wave propagation
171
What is a standing wave?
Have defined nodes and antinodes that do not move with wave propagation
172
If two waves are out of phase at any interval besides 180 degrees, how does the amplitude of the resultant waves compare to the amplitudes of the two interfering waves?
Perfectly in phase = amplitude is equal to the sum of the amplitudes of the interfering waves ; perfectly out of phase = amplitude is equal to the difference of the amplitudes of the interfering waves
173
True or False: Sound waves are a prime example of transverse waves
FALSE, sound waves = longitudinal waves
174
How does applying a force at a natural frequency of a system change the system?
The object will resonate because the force frequency = the natural (resonant) frequency, amplitude of the oscillation will increase
175
How is sound produced and transmitted?
Mechanical vibrations (usually generated by solid objects like bells or vocal cords), but occasionally can be generated by fluids, propagated as longitudinal waves in matter
176
To which properties of a sound wave do amplitude and frequency correspond?
Amplitude is related to its sound level (volume), frequency is related to its pitch
177
If two objects are traveling toward each other/away from each other/one is following the other, how does the apparent frequency differ from the original frequency?
Traveling towards each other = apparent frequency > original frequency ; traveling away from each other = apparent frequency < original frequency ; one following the other = apparent frequency could be greater or less than original frequency
178
An opera singer has two precisely identical glasses. The singer produces as pure a tone as possible and shatters the first glass at a frequency of 808 Hz. She then sings a frequency of 838 Hz in the presence of the second glass. The second glass will likely:
Not shatter because the applied frequency is not equal to the natural frequency of the glass
179
What is a true statement about frequency, angular frequency, and period of a given wave?
The magnitude of the angular frequency is larger than the magnitude of the frequency
180
A student is measuring sound frequencies from the side of a road while walking east. For which of the following situations could the student determine that the difference between the perceived frequency and the actual emitted frequency is zero?
A dog barking in a car that moves east (would only be zero if moving in the same direction)
181
In which of the following media does sound travel the fastest?
Glass
182
Shock waves have the greatest impact when the source is traveling:
Exactly at the speed of sound
183
Ignoring attenuation, how does the intensity of a sound change as the distance from the source doubles?
It is one-quarter as intense
184
Order the types of electromagnetic radiation from lowest to highest energy/frequency.
Radio < Micro < Infrared < Visible < UV < X-rays < Gamma
185
True or False: Light waves are longitudinal because the direction of propagation is perpendicular to the direction of oscillation
FALSE! Light waves are transverse waves
186
What are the boundaries of the visible spectrum? How does the range of the visible spectrum compare to the range of the full electromagnetic spectrum?
ROYGBIV (700 -> 400 nm, increases in frequency)
187
What do the signs of variables mean for mirrors?
Positive o = in front of mirror, Negative o = behind mirror ; Positive i = in front of mirror (real) , Negative i = behind mirror (virtual) ; Positive r = concave (converging) , Negative r = convex mirror (diverging) ; Positive f = concave (converging) , Negative f = convex (diverging) ; Positive m = image is upright, Negative m = image is inverted
188
What do the signs of variables mean for lenses?
Positive o = on same side of lens, Negative o = on opposite side of lens ; Positive i = opposite side of lens (real) , Negative i = same side of lens (virtual) ; Positive r = convex (converging) , Negative r = concave mirror (diverging) ; Positive f = convex (converging) , Negative f = concave (diverging) ; Positive m = image is upright, Negative m = image is inverted
189
What is dispersion? What is aberration?
Dispersion = the tendency for different wavelengths of light to experience different degrees of refraction in a medium, leading to a separation of light into the visible spectrum (a rainbow) ; Aberration = the alteration or distortion of an image as a result of an imperfection in the optical system
190
How does the diffraction pattern for a single slit differ from a slit with a thin lens?
Diffraction through a single slit does not create characteristic fringes when projected on a screen, although the light does spread out. When a lens is introduced into the system, the additional refraction of light causes constructive and destructive interference, creating fringes.
191
What wave phenomenon do diffraction fringes result from?
Constructive and destructive interference between light rays
192
How does double-slit diffraction and interference differ from single-slit diffraction?
The image formed during double-slit diffraction contains fringes because light rays constructively and destructively interfere. A single slit forms an image of a wide band of light, spread out from its original beam
193
True or False: Maxima in diffraction patterns are always equidistant between two minima
True (maxima and minima alternate in a diffraction pattern)
194
Contrast plane-polarized and circularly polarized light.
Plane-polarized light contains light waves with parallel electric field vectors. Circularly polarized light selects for a given amplitude and has a continuously rotating electric field direction.
195
How does the application of a polarized filter impact the wavelength of light passing through the filter?
Plane polarization has no effect on the wavelength (or frequency or speed) of light. Polarization does affect the amount of light passing through a medium and light intensity.
196
If a light ray has a frequency of 5.0 x 10^14 Hz, in which region of the electromagnetic spectrum is it located?
c = f * lambda -> (3 x 10^8 m/s) / (5 x 10^14 Hz) = 6 x 10^-7 m = 600 nm = visible light
197
A child stands between two mirrors with his arms out, perpendicular to the mirrors. One plane mirror is 5 m away from his left hand and another plane mirror is 7 m away from his right hand. How far apart are the two images produced by the mirrors if the child has an arm span of 0.5 m?
Plane mirror is as far away from the image as the object is -> 7 + 7 + 5 + 5 + 0.5 = 24.5 m
198
An object is placed at the center of curvature of a concave mirror. Which of the following is true about the image?
1/f = 1/i + 1/o -> 1/f = 1/i + 1/2f -> 1/2f = 1/i -> i = 2f (Positive = real image, then has to be inverted)
199
A ray of light (f = 5 x 10^14 Hz) travels from air into crystal into chromium. If the indices of refraction of air, crystal, and chromium are 1, 2, and 3, respectively, and the incident angle is 30 degrees, then which of the following describes the frequency and the angle of refraction in the chromium?
5 x 10^14 Hz; 9.6 degrees (angle of refraction < incident angle)
200
A source of light (f = 6.0 x 10^14 Hz) passes through three plane polarizers. The first two polarizers are in the same direction, while the third is rotated 90 degrees with respect to the second polarizer. What is the frequency of the light that comes out of the third polarizer?
Light will not pass through the third polarizer
201
Which of the following describes the image formed by an object placed in front of a convex lens at a distance smaller than the focal length?
Virtual and upright (in front of focal point = has to be virtual)
202
A submarine is inspecting the surface of the water with a laser that points from the submarine to the surface of the water and through the air. At what angle will the laser not penetrate the surface of the water but rather reflect entirely back into the water?
sin (1/1.33) = 0.75 -> sin 45 = sqrt 2 / 2 = 0.707 = 48.59 degrees
203
A student is analyzing the behavior of a light ray that is passed through a small opening and a lens and allowed to project on a screen a distance away. What happens to the central maximum (the brightest spot on the screen) when the slit becomes narrower?
The central maximum becomes wider (equation: asintheta = n*lambda -> a decreases, sin theta increases because n*lambda is constant for a given slit)
204
Monochromatic red light is allowed to pass between two different media. If the incident angle in medium 1 is 30 degrees and the incident angle in medium 2 is 45 degrees, what is the relationship between the speed of the light in medium 2 compared to medium 1?
Using Snell's law and n = cv, it becomes c1/v1 sin theta 1 = c2/v2 sin theta 2 -> sin 30/v1 = sin 45/v2 -> v2 = v1 sqrt (2)
205
A scientist looks through a microscope with two thin lenses with m1 = 10 and m2 = 40. What is the overall magnification of this microscope?
Magnification = 10 * 40 = 400
206
Imagine that a beam of monochromatic light originates in air and is allowed to shine upon the flat surfacce of a piece of glass at an angle of 60 degrees with the normal. The reflected and refracted beams are perpendicular to each other. What is the index of refraction of the glass?
Snell's Law -> n1sintheta1 = n2sintheta 2 -> sin 60 = n2 sin 30 -> n2 = sqrt (3)
207
What is the approximate partial pressure of oxygen at 1500 m?
Dalton's Law : 0.84 atm * 0.21 = 0.716 atm ~ 0.18 atm
208
A climber using bottled oxygen accidentally drops the oxygen bottle from an altitude of 4500 m. If the bottle fell straight down this entire distance, what is the velocity of the 3-kg bottle just prior to impact at sea level?
As an object falls, KE would end up equaling PE -> 1/2m(vfinal)^2 = mgh -> 1/2 (3)(vfinal)^2 = 3(10)(4500) -> vfinal = 300 m/s
209
Fluid pressure changes with depth are assumed to be linear. Which statement best explains why this does not hold true for atmospheric pressure changes?
The volume of a mass of air is not constant
210
Which of the following most closely approximates the pKa of phenolphthalein?
9.3 (cannot be under 7)
211
What is the letter for the amino acids asparagine and phenylalanine?
N and F
212
Which of the following phase changes are exothermic processes?
Liquid to solid, gas to solid (solids and liquids have less heat energy than gas)
213
When 2 moles of HF are added to 100 mL of water, the resulting solution has a pH equal to 4. What is the percent dissociation of HF?
Original [HF] = 2 mol/0.100 L = 20 M -> [H+]/[HF] = (10^-4 M)/(20 M) = 5 x 10^-6 -> % dissociation = 5 x 10^-6 x 100 = 5 x 10^-4 = 0.0005%
214
An object with a mass of 10 kg is rolled down a frictionless ramp from a height of 3 meters. If a factory worker at the bottom of the ramp slows the object until it comes to a stop, how much work must the factory worker have done? (Assume g = 10 m/s^2)
Gravitational potential energy = 10*10*3 = 300 J -> work-energy theorem says that Wnet = change in KE -> delta KE = 300 J
215
What is the wavelength of the photons emitted by the 145Pm-m?
Lambda = hc/E -> (6.62 x 10^-34 J*s)(3 x 10^8 m/s) / (300 x 10^3 eV)(1.6 x 10^-19) = 4.1 x 10^-12 m
216
In order to find the concentration of metal ions needed to determine the distribution coefficient of copper (II), what calculation could the researchers have performed in addition to the procedure described in the passage?
Subtract the concentration of metal ions in the aqueous phase after extraction from the concentration before extraction
217
Following extraction into chloroform, the spectrophotometric absorbance at 820 nm of copper in aqueous solution will be greatest at which pH?
5.15 (the aqueous solution pH in which log D is smallest for the extraction of chloroform)
218
In the electron transport chain, which of the following is the component that is reduced but never oxidized?
Oxygen (is reduced to yield H2O, but is never shown to become oxidized)
219
What is a molecule with a carboxylic acid functional group that has a high Ka?
CH3CF2COOH (higher Ka = more acidic)
220
A 50-kg child is riding on a playground merry-go-round. If the radius of the circular path of the merry-go-round is 5.0 m and the frequency is 0.1 hertz, what is the force required to keep the child on the ride?
Centripetal force -> have to calculate speed first -> V = 2pi*r/T = 2(3.14)(5.0 m)/(10 s) = 3.14 m/s, then calculate centripetal force -> Fc = mv^2/r = (50 kg)(3.14 m/s)^2/(5.0 m) ~ 100 N
221
Cefimixe displays what inhibitive behavior on PBP?
Only irreversible enzyme inhibitor = suicide inhibitor
222
If a strong base solution used in the titration curve shown was 0.10 M sodium hydroxide and the volume of the glycine solution titrated was 20.0 mL, what was the molarity of the glycine solution?
15 mL NaOH * (0.10 mole/L) * (1 glycine/1 NaOH) * (1/20 mL) = 0.075 moles/L
223
Which of the following represents the pH of the isoelectric point for glycine?
On a titration curve, this can be approximated by averaging the midpoints of the two plateau regions
224
What is the mechanical advantage of using the ramp, as opposed to lifting the gurney straight up? (Ignore any effects of friction)
MA = hypotenuse / height = 2x / x = 2
225
Two identical gurneys are placed side-by-side on a ramp with their wheels locked to eliminate spinning. Gurney 1 has a dummy placed on it to give it a total mass of 200 kg, while Gurney 2 is loaded with a dummy that makes it only 50 kg overall. If the ramp has a coefficient of friction of ustatic, which gurney is more likely to slide down the ramp?
They are equally likely to slide down the ramp (gurney with a larger mass also has a larger static frictional force)
226
A circuit is comprised of a 12-volt battery with three light bulbs with the same resistance. If two of the light bulbs are wired in parallel and are in series with the three light bulb, what happens when one of the parallel light bulbs is unscrewed?
Two of the light bulbs remain lit
227
Air is bubbled through distilled water. The solution will have a pH:
Less than 7, because carbon dioxide undergoes hydrolysis (carbon dioxide -> carbonic acid, pH < 7)
228
What is the approximate pH of a saturated aqueous solution of hydrochloric acid whose molarity is 10.6 M?
Saturated HCl would completely dissociates in aqueous solution, pH = -log [OH] = -log [10] = -log [10^1] = -1
229
Which molecule will have the highest Rf value studied with thin-layer chromatography using a silica plate?
CH3CH2CH2CH2CH3 (the most nonpolar compound)
230
Atherosclerosis, a particular type of arteriosclerosis, usually involves either complete blockage or severe restriction of blood flow due to high cholesterol and buildup of plaque in the arteries. In extreme cases, constricted arteries may collapse under pressure from outside the arteries. This can best be explained by:
The necessary increase in fluid velocity through the constricted arterial sections causing a corresponding drop in fluid pressure
231
An artificial heart valve was tested for its ability to function under extreme conditions, to a maximum flow rate of 4.00 x 10^-4 m^3/s. What speed would this correspond to for an average red blood cell within a blood vessel of cross-sectional 5.00 x 10^-6 m^2?
Speed = (4 x 10^-4 m^3/s) / (5 x 10^-6 m^2) = 8 x 10^ 1 m/s
232
Underproduction of pulmonary surfactant in IRDS leads to decreased compliance of alveolar tissue. Based upon this information, which of the following must be true regarding pulmonary surfactant?
Its adsorption to the water-alveolar interface decreases surface tension, decreasing the pressure difference required to inflate the airway
233
What occurs doing inspiration?
Contraction of the diaphragm and external intercostal muscles -> expansion of the thoracic cavity, decrease in intrapleural pressure (negative pressure relative to atmosphere causes airflow through the respiratory tree)
234
For an interaction to be spontaneous...
The free energy change of the reaction must be negative
235
Which of the following electronic transitions for a hydrogen atom would result in the emission of a photon that would be visible to the human eye?
n = 4 to n = 2 ( E = Rydberg constant (1 x 10^7 m^-1) / n^2)
236
The transition from N to O offers an exception to the trend for first ionization energy due to Hund's rules of spin pairing. If this spin pairing was not present, what would be the expected first ionization energy for the p-orbital on an oxygen atom?
There is a trend exception from group 5 to group 6 (ionization energy would be higher if there was no drop in IE)
237
Which of the following explains the observations made by Rutherford?
Most of the volume of the gold atom is empty space, the alpha particles and the gold nuclei are both positively charged
238
Which of the following types of electromagnetic radiation would have the shortest wavelength?
Radiation that ejects an electron from an sp orbital (shorter wavelength = higher energy; sp = triple bond)
239
A person pushes horizontally on a 50-kg crate, causing it to accelerate from rest and slide across the surface. If the push causes the crate to accelerate at 2.0 m/s^2, what is the velocity of the crate after the person has pushed the crate a distance of 6 meters?
Vf^2 = Vi^2 + 2ad = 0^2 + 2(2)(6) = 5 m/s
240
Does lithium have the second largest atomic radius in period 2?
No
241
How much heat is produced from the complete combustion of 30 g of methane, if the enthalpy of reaction is -890 kJ/mol?
30 g CH4 x (1 mol/16 g) x (890 kJ/mol) = 1.8 x 10^3 kJ
242
What is the exclusion limit of the SEC column used to create the calibration curve shown in Figure 2?
If log (MW) = 6, MW = 10^6 Da = 10^3 kDa = 1000 kDa
243
What is affinity chromatography?
Used to separate molecules, including proteins, based upon their specific interaction with the stationary phase
244
What is ion-exchange chromatography?
The ion listed is the one that takes longer to elute (ex. cation exchange chromatography = negatively charged resin, cation bind and take longer to elute)
245
What is SDS-PAGE?
An electrophoretic technique which involves the binding of the anionic detergent SDS to a polypeptide chain (fractionation by approximate size alone during electrophoresis)
246
What is NMR spectroscopy?
Not a separatory technique (can fraction a protein sample based on only molecular weight)
247
More complete fractionation of proteins using an SEC column could be achieved by using a:
Longer column
248
Selenocysteine is a non-standard amino acid that is present in all domains of life. It has the structure of cysteine, but the sulfur atom is replaced with selenium. What is the absolute configuration of the alpha carbon in selenocysteine?
R (R, S = absolute configuration; D, L = relative configuration)
249
Which acids (HF, HCl, HBr, and HI) is a weak acid in aqueous solution?
HF
250
What is the pH of a 0.10 M aqueous solution of acetylsalicylic acid?
Ka = [H+][A-]/[HA] -> 10^-35 = x^2/0.1 -> pH = 2.25
251
A student determined that her yield of aspirin was 3.9 g. What was her percent yield?
3.5 x 10^-2 mol * 180 g/mol ~ 7g -> 4/7 = 60%
252
Salicylic acid is a benzoic acid derivative which can most directly be obtained through the Kolbe-Schmitt carboxylation of:
A phenol
253
Which pair of enzymes, if used simultaneously, will produce the greatest amount of glucose if the experiment is repeated?
The pair of enzymes that have the maximum current/absorbance
254
How would the absorbance at 570 nm change over time for enzyme A if a linear starch was used?
Enzyme A would break down linkages, forming more linear polysaccharides, but if the initial starch is entirely linear, than a debranching enzyme would have no effect on absorbance
255
Phosphorous acid, a common ingredient used for portable water treatment, has a molecular formula of:
H3PO3
256
During strenuous exercise, lactic acid buildup in cells causes the creation of a hydronium complex known as the Eigen cation (H9O4+). If water molecules then experience hydrogen bond attractions to the Eigen cation, this attractive force:
Results in a semi-stable shell of water molecules around the hydronium
257
If a 3-kg rabbit's leg muscles act as imperfectly elastic springs, how much energy will they hold if the rabbit lands from a height of 0.5 m and its legs are compressed by 0.2 m?
PE = (3)(10)(0.5) = 15 J, which is a bit of an overestimate, closest to 10 J
258
When does a runner output the most additional energy to keep the ground reaction forces most nearly vertical and through her body's center of mass?
When she takes high, bouncing strides and leans her upper half into her run
259
A 60-kg runner raises his center of mass approximately 0.5 m with each step. Although his leg muscles act as a spring, recapturing the energy each time his feet touch down, there's an average 10% loss with each compression. What must the runner's additional power output be to account for just this loss, if he averages 0.8 s per stride?
PE = (60 kg)(10 m/s^2)(0.5 m) = 300 J -> 10% of 300 J = 30 J -> Power = (30 J)/(0.8 s) = 40 W
260
Which of the following best explains why arginine is more basic than lysine?
The electron-donating groups around the basic nitrogen on arginine make its conjugate acid more stable
261
In a flat Petri dish contaning a single layer of cells suspended in viscous culture medium is tapped, some cells will collide into each other. If cell 1 collides into cell 2 on such a plate, which of the following describes what happens to cell 2 after the collision, assuming that it undergoes an elastic collision and experiences drag from the medium?
Cell 2 moves with decreasing speed, Cell 2 decelerates until it reaches a velocity of 0 m/s
262
Balance the following redox reaction using the half-reaction method: Mg (s) + HNO3 (aq) -> Mg2+ (aq) + NO (g)
2 HNO3 + 3 Mg + 6 H+ -> 2 NO + 3 Mg2+ + 4H2O
263
A sample is assayed for lead by a redox titration with I3- (aq). A 10.00 g sample is crushed, dissolved in sulfuric acid, and passed over a reducing agent so that all the lead is in the form Pb2+. The Pb2+ (aq) is completely oxidized to Pb4+ by 32.60 mL of a 0.7 M solution of NaI3. The balanced equation for the reaction is: I3- + (aq) + Pb2+ (aq) -> Pb4+ (aq) + 3I- (aq). Calculate the mass of lead in the sample.
0.7 M I3- (32.60 x 10^-3 L) (1 mol Pb2+/1 mol I3-) (207.2 g Pb2+/1 mol Pb2+) ~ 4.2 g
264
Consider the following equation: 6 Na (s) + 2 NH3 (aq) -> 2Na3N (s) + 3 H2 (g). Which species acts as an oxidizing agent?
H in NH3
265
As methanol is converted to methanal, and then methanoic acid, the oxidation number of the carbon:
Increases
266
If a certain metal has multiple oxidation states, its acidity as an oxide generally increases as the oxidation state increases. Therefore, which of the following tungsten compounds is likely to be the strongest acid?
WO3
267
What is a disproportionation reaction?
When a reactant results in two different oxidation states in two different products
268
The equation is Au + NaCN + O2 + H2O -> Na [Au(CN)2] + NaOH. An indicator is used during this reaction, and approximately 100 mL of a 2M NaCN solution is used to reach the endpoint. How many moles of Au are present in the crushed ore?
Balanced equation: 4Au + 8NaCN + O2 + 2H2O -> 4Na [Au(CN)2] + 4NaOH -> 0.1 L * 2 mol/L = 0.2 mol NaCN -> 0.2 mol * 4 mol Au/8 mol NaCN = 0.1 mol Au
269
What statements describe a galvanic (voltaic) cell?
Anode = site of oxidation, current flows cathode -> anode, anode has a negative designation, electrons flow anode -> cathode
270
What statements describe an electrolytic cell?
Anode = site of oxidation, current flows cathode -> anode, cathode has a negative designation, electrons flow anode -> cathode
271
Write the cell diagram for the discharging state of a lead-acid battery.
Pb (s) I H2SO4 (4 M) II H2SO4 (4 M) I PbO2 (s)
272
How much current is required to produce 0.23 kg Na from a molten NaCl electrolytic cell that runs for 30 hours? Assume the cell is 100% efficient.
mol M = It/nF -> I = (mol M)nF / t = (230 g/23 g/mol) (1 mol e-)(96,485 C/mol e-) / 30 hr (3600 s / 1 hr) = 10 A
273
How are standard reduction potentials measured?
Setting up a cell relative to a standard hydrogen electrode, which is given a reduction potential of 0 V by convention
274
What does it mean if the emf is positive/negative?
Positive emf = spontaneous (galvanic); negative emf = nonspontaneous (electrolytic)
275
If Keq is very large, the reaction is ___. If Keq is very small, the reaction is ____.
Spontaneous/nonspontaneous
276
An electrolytic cell is filled with water. Which of the following will move toward the cathode of such a cell?
H+ ions and electrons
277
What type of compound is least likely to be found in the salt bridge of a galvanic cell?
SO3 (not an ionic compound)
278
If the surface area of electrode material in an electrochemical cell is tripled, what else is necessarily tripled?
Current
279
Which of the following can alter the emf of an electrochemical cell?
The temperature of the solutions in the half-cells
280
Which equation describes the relationship between standard electromotive force and standard change in free energy?
Delta G = nF(Ered,anode - Ered,cathode)
281
Which of the following is the best explanations for the fact that a larger mass of electrodes are required for lead-acid batteries, as compared to other batteries, to produce a certain current?
The energy density of lead-acid electrodes is lower than that of other batteries
282
Which of the following best describes why overcharging a Ni-Cd battery is not detrimental?
The Ni-Cd battery will stop accepting electrons from an outside source when its electrodes are recharged
283
How does the work function relate to the energy necessary to emit an electron from a metal?
Work function = minimum amount of energy necessary to emit an electron, any additional energy from a photon will be converted to excess kinetic energy during the photoelectric effect
284
What does the threshold frequency depend upon?
The chemical composition of a material (the identity of the metal)
285
What electrical phenomenon results from the application of the photoelectric effect?
The accumulation of moving electrons creates a current during the photoelectric effect
286
What determines the absorption spectrum of a single atom?
The energy differences between ground-state electrons and higher-level electron orbits
287
True or False: small changes in chemical structure only minimally impact light absorption and emission patterns.
FALSE
288
During which electronic transitions is photon emission most common?
When electrons transition from a higher-energy state to a lower-energy state
289
What causes fluorescence?
The special stepwise photon emission in which an excited electron returns to the ground state through one or more intermediate excited states. Each energy transition releases a photon of light. With smaller energy transitions than the initial energy absorbed, these materials can release photons of light in the visible range.
290
What is strong nuclear force?
One of the four primary force, provides the adhesive force between the nucleons (protons and neutrons) within the nucleus
291
What is mass defect?
The apparent loss of mass when nucleons come together, as some of the mass is converted into energy
292
What is binding energy?
The energy that mass is converted into energy from nucleons in mass defect (when mass is converted into energy)
293
What are the four fundamental forces of nature?
Strong and weak nuclear forces, electrostatic forces, and gravitation
294
How does the mass defect relate to the binding energy?
E = mc^2
295
True or False: Nuclear fission and nuclear fusion both release energy.
TRUE
296
Compare and contrast nuclear fission and nuclear fusion reactions.
Fission = large reactants, decreases nuclear mass; fusion = small reactants, increases nuclear mass
297
What is alpha decay?
Emits alpha particle, mass number - 4, atomic number - 2
298
What is beta-negative decay?
Emits an electron and an antineutrino, mass number + 1
299
What is beta-positive decay?
Emits a positron and a neutrino, atomic number - 1
300
What is gamma decay?
Emits a massless gamma ray
301
What is electron capture?
Emits nothing (absorbs an electron from inner shell), mass number - 1
302
How many half-lives are necessary for the complete decay of a radioactive sample?
Because the amount remaining is cut in half after each half-life, the portion remaining will never quite reach zero.
303
Which type of nuclear decay could be detected in an atomic absorption spectrum?
Because gamma radiation produces electromagnetic radiation, it can be detected on an atomic absorption spectrum
304
If the work function of a metal is 6.622 x 10^-20 J and a ray of electromagnetic radiation with a frequency of 1.0 x 10^14 Hz is incident on the metal, what will be the speed of the electrons ejected from the metal?
KE = hf - W -> KE = 1/2mv^2 -> v = sqrt (2KE/m)
305
What are some true statements about the Bohr model of the atom?
Energy levels of the electron are stable and discrete, an electron emits or absorbs radiation only when making a transition from one energy level to another, to jump from a lower energy to a higher energy orbit, an electron must absorb a photon of precisely the right frequency such that the photon's energy equals the energy difference between the two orbits.
306
Ultraviolet light is more likely to induce a current in a metal than visible light. This is because photons of ultraviolet light:
Have a higher energy
307
What are some true statements about the photoelectric effect?
KE of emitted electrons do not depend on light intensity, a weak beam of light of frequency greater than the threshold frequency yields more current than an intense beam of light of frequency lower than the threshold frequency, for light of a given frequency the kinetic energy of emitted electrons increases as the value of the work function decreases
308
A graph of the exponential decay process is created. The y-axis is the natural logarithm of the ratio of the number of intact nuclei at a given time to the number of intact nuclei at time t = 0. The x-axis is time. What does the slope of such a graph represent?
n = n0e^-lambda*t -> ln(n/n0) = -lambda*t -> ln (n/n0) = --lambda
309
The half-life of carbon-14 is approximately 5730 years, while the half-life of carbon-12 is essentially infinite. If the ratio of carbon-14 to carbon-12 in a certain sample is 25% less than the normal ratio in nature, how old is the sample?
Less than 5730 years
310
What reagants are likely to be used to form the Britton-Robinson buffer solution?
A polyprotic weak acid and Na2HPO4 (if the pH is acidic, bases CANNOT be in the buffer)
311
What does UV spectroscopy show?
NOT BONDS (IR spectroscopy shows presence of bonds)
312
Between absorption, refraction, scattering, and amplification, which phenomena does not serve to attenuate the ultrasound signal as it passes through the body?
Amplification
313
What is the range of human hearing?
20 Hz to 20 kHz
314
A certain metabolic process in the liver produces NADH as a part of the process. If this process is up-regulated, which of the following effects associated with gluconeogenesis is most likely to follow?
The rate of gluconeogenesis in the liver will decrease (low conversion of NAD+ to NADH -> low concentration of pyruvate and OAA -> low rate of gluconeogenesis)
315
The conversion between glucose and pyruvate strongly favors the formation of pyruvate, and yet the gluconeogenic pathway is able to utilize several shared enzymes with glycolysis to create glucose from pyruvate. It is able to do this primarily because:
The formation of glucose, fructose-6-phosphate, and PEP through gluconeogenesis-specific enzymes push the equilibrium of reactions catalyzed using shared
316
What type of capacitor would have the greatest total capacitance?
One where the capacitors are attached in parallel
317
What increases the rate of a reaction?
Increasing the temperature
318
Aspartame (N-L-alpha-aspartyl-L-phenylalanine 1-methyl ester) is a very well-known artificial sweetener found in the large majority of non-sugar containing food products. This compound is classified as a:
Dipeptide (contains 2 amino acids)
319
What is the equation for efficiency?
Efficiency = output work/input energy
320
What is a Joule equal to?
m^2 * kg / s^2
321
What does a tertiary amine mean?
There are 3 nitrogen groups in the structure
322
What type of melting point range would result in a lot of impurities?
A large range
323
The retention factor in a TLC procedure depends on:
Solvent system, temperature, and the absorbent
324
What situation would result in the greatest risk for TBI?
Riding a roller coaster of 9 m/s^2 for 40 s (HIC = m* (9 m/s^2)(40 s) = 360 m * Ns
325
What is the minimum ramp height H if the ride at the top of the loop maintains the minimum speed needed to stay on the track throughout the loop? (r = 8 m)
Ef = mgH + 1/2mv^2 = mg(2r) + 1/2mv^2 -> Ef = 2mgr + 1/2mgr = (5/2)mgr -> H = 5r/2 -> H = 5(8)/2 = 20 m
326
To construct the best possible buffer:
The organic acid with the pKa closest to the pH where the experiment will take place
327
If negative charge repulsion in C4S units contributes to the elastic modulus of articular cartilage, given passage information, which of the following is likely observed as a result of OA in articular cartilage?
Decreased charge repulsion and decreased compressive strength
328
What is the pH of a 0.010 M perchloric acid solution?
2
329
A large steel water storage tank with a diameter of 20 m is filled with water and is open to the atmosphere (1 atm = 101 kPa) at the top of the tank. If a small hole rusts through the side of the tank, 5.0 m below the surface of the water and 20.0 m above the ground, assuming wind resistance and friction between the water and steel are not significant factors, how far from the base of the tank will the water hit the ground?
Bernoulli's equation: P1 + pgy1 + 1/2pv1^2 = P2 + pgy2 + 1/2pv2^2 -> -gy2 = 1/2v2^2 -> v = 10 m/s -> d = vi*t + 1/2gt^2 -> t = 2 seconds -> d = vi*t = (10 m/s)(2 s) = 20 m
330
Tollens' test typically involves exposure of a carbohydrate to a solution of CuO in ammonia (NH3). Glucose yields a positive Tollens' test, but sucrose does not. Which of the following best explains this fact?
Glucose contains a hemiacetal group, while sucrose does not; this classifies glucose as a reducing sugar
331
If the average pitcher is releasing the ball from a height of 1.8 m above the ground, and the pitcher's mound is 0.2 m higher than the rest of the baseball field, at what height would the catcher need to hold his glove to catch the pitched ball?
Ball's flight time = (18 m) / (30 m/s) = 0.6 s -> d = v0t + 1/2 at^2 -> (0 m/s)(0.6 s) + 1/2 (10m/s^2)(0.6 s)^2 = 1.8 -> 2-1.8 = 0.2
332
Towards the end of a game, a team's pitcher begins to lose his focus and shortens his stride, uncoupling the kinetic chain at his hips. How will this impact his pitch?
It will decrease the velocity of the pitch due to a decrease in energy transfer through the torso
333
If the majority of the baseball's kinetic energy comes from power generation in the legs and hips, approximately how much energy do the lower extremities produce in the pitch?
KE = 1/2 (0.15 kg)(30 m/s)^2 = 67.5 J -> Efficiency = (0.9)(0.9)(0.7)(0.8) = 0.5 -> 67.5 J/0.5 = 135 J
334
While evaluating the timing of pitches, the researchers noticed a couple of high-performing athletes who were able to generate higher velocities by increasing their length of their acceleration phase. How did the power production for these athletes compare to those originally mentioned?
There may have been no change in power output between the two groups
335
If researchers failed to take into the account the effect of air resistance on the pitch, how would it impact their measurements of the efficiency of energy transfer from the arm to the baseball?
It would be lower than the actual efficiency, as there was a higher initial velocity at release
336
What makes a reaction spontaneous?
Positive delta S, negative delta H
337
Antioxidant activity is an important function of which of the following vitamins?
Vitamin E
338
When Bs1A is assembled as an octamer, what is most likely to be true regarding L76, L77, and L79?
The assembly would incur an entropic penalty if they occupied a solvent-exposed site
339
A scientist uses an ultrasound device mounted to a vehicle to measure fluid flow underground. The device makes use of the Doppler effect to track fluid movement in the water table. Which of the following scenarios is most likely to produce a readable Doppler shift?
The fluid is flowing at a velocity twice that of the sound-emitting device, in the same direction as the device is moving
340
Presbyopia is diagnosed when the lens of the eye focuses incoming light rays to a position between the retina and the choroid. Which type of lens should be placed in front of the eye to focus light on the retina and correct this condition?
Converging lens
341
Besides directly killing bacteria, how does pasteurization with hot water treat IPB populations?
By decreasing the solubility of oxygen, preventing further bacterial oxygen
342
In locations with very low dissolved O2 concentrations in drinking water, the observed Ksp of ferrous (II) hydroxide will be:
The same
343
If an IR absorption spectrum were obtained for the dimer, a strong signal at 1750 cm^-1 would most likely indicate the presence of:
A C=O bond
344
What does downstream mean in NMR?
Higher E value
345
A pure sample of (R)-limonene has a specific rotation of +125.6. If a mixture of (R)-limonene and (S)-limonene has a specific rotation of +62.8, what are the percentages of the R and S enantiomers in this mixture?
75% R, 25% S
346
A patient presents in the emergency department having ingested a large quantity of tolbutamide. Intavenous administration of which of the following compounds is most likely to increase the rate of urinary excretion of the drug?
NaHCO3
347
The equivalence point of the titration of tolbutamide with NaOH was reached by adding 50 mL of NaOH. What describes the solution during this process?
After addition of 25 mL of NaOH, the pH of the solution was greater than 5
348
During the initial reduction reaction, FAD receives how many protons and how many electrons from cholesterol?
1 proton and 1 electron
349
Which of the following solvents would lead to the fastest SN1 reaction?
Propanol (a protic solvent)
350
If the tympanic membrane has three times the diameter of the oval window (to amplify sound as it is transmitted through the ossicles) how would it impact the results if the same experiment was performed on a mouse whose tympanic membrane had not been bypassed?
The higher intensity would have no impact on the curve (would not impact amplitude/frequency)
351
When the outer hair cells vibrate, they generate a standing wave in the closed organ of Corti, which amplifies the frequency of interest at particular locations along the basilar membrane. How will the length of the enclosed space within the organ of Corti vary along the length of the basilar membrane to explain this?
The length of the enclosed space in the organ of Corti will increase linearly from the base to the apex of the cochlea
352
The distance between the ears for an average adult male is 20 cm. If a wave with a frequency of 17,000 Hz hits both the right and left ear and has a phase difference of 5π radians between the two, what is the difference in distance between the origin of the sound and each ear (velocitysound in air = 343 m/s)?
(5pi radians) / (2pi radians) = 2.5lambda -> lambda = v/f -> 343 m/s / 17000 Hz = 2 cm -> 2.5 (2) = 5 cm
353
If a signal is transmitted along a segment of nerve axon measuring 5 x 10-4 m, how much time is required for the signal to reach the end of the segment, assuming maximal transmission velocity?
5 x 10^-4 / 200 m/s = 2.5 x 10^-6 s
354
The capacitance of a nerve membrane can be increased by:
Decreasing the width of the membrane
355
An unknown fluid has a specific gravity of 0.750. What is the volume of 22.5 kg of this fluid?
22.5 kg x (1 m^3/750 kg) x (1000 L/1 m^3) = 30 L
356
What are properly balanced complete combustion reactions?
CH4 (g) + 2 O2 (g) -> CO2 (g) + 2 H2O (l) ; C3H8 (g) + 5 O2 (g) -> 3 CO2 (g) + 4 H2O (l) ; C2H5OH (l) + 3 O2 (g) -> 2 CO2 (g) + 3 H2O (l)
357
If the volume of the system is halved:
The concentration of the product will increase
358
If a reaction is endothermic:
It requires energy for the reaction to proceed
359
The auto-ionization of water is an endothermic process. With this in mind, if the temperature of a beaker of pure water is increased:
The pH of the water will decrease
360
What is the equation for the auto-ionization of water?
2H2O (l) -> H3O+ (aq) + OH- (aq)
361
Nickel-cadmium (NiCd) batteries are rechargable cells used in products ranging from remote-control toys to airplanes. An NiCd battery in the process of discharging is most analogous to:
A galvanic cell (has a positive cathode)
362
A slingshot propels a rubber ball horizontally from a platform 30 m off the ground at 15 m/s. Approximately how far from the base of the platform will the ball land?
Initial vertical velocity = 0 m/s -> delta X = Vot + 1/2at^2 -> 30 m = 1/2 (10 m/s^2) -> t ~ 2.5 -> Range = (15 m/s)(2.5 s) = 37.5 m
363
A 10-kg sled rests on a 30° ramp with a coefficient of static friction of 0.5. An upward force is applied to the sled, parallel to the slope of the ramp, in incremental values until the sled begins to accelerate up the ramp. Approximately what minimum force is required to perform this action?
Fapplied = Fg + Fs -> mgsin30 = (10 kg)(10 m/s^2)(0.5) = 50 N -> Fs = (umg cos 30) = (0.5)(10 kg)(10 m/s^2)(0.866) = 43.3 N -> F applied = 93.3 N
364
The moon's orbit around the Earth is approximately circular. How much work is done on the moon by the force of gravity when the moon completes half an orbit around the Earth? (Note: radius of moon's orbit: 3.85 × 105 m; mass of Earth: 6 × 1024 kg; mass of moon: 7.3 × 1022 kg; moon orbital time: 27 days)
W = Fdcostheta = 0
365
A hoop and a sphere, each of mass M, are rolled down a frictionless ramp. At the bottom of the ramp, which object will have the greater translational velocity, and why?
The sphere, because its moment of inertia is lower
366
600 mL of 1.5 M benzene-1,4-dicarboxylic acid (C8H6O4), one of the primary reagents used in the manufacture of Kevlar, is diluted with 2.4 L of water. What is the final molarity of the solution?
M1V1 = M2V2 -> M2 = (M1V1)/V2 = (0.6 L x 1.5 M) / 3 L = 0.30 M
367
A well-sealed flask found in a laboratory is said to contain a 1.5 M solution of an unidentified compound. The solution is measured to be 3.5 L and to have a density of 0.5 g/mL. What is the molar mass of this compound?
(1.5 mol compound / 1000 mL) x (1 mL / 0.5 g) = 0.003 mol/g, or 333 g/mol
368
What is a statement about boiling point?
If the vapor pressure of water is 38 mmHg in a near-vacuum environment with a Patm of 0.05 atm, it wil boil (vapor pressure = atmospheric pressure)
369
As increasing amounts of NaCl are added to water:
Boiling points will increase, melting point will decrease, and vapor pressure will decrease
370
When an infrared ray transitions from air (n=1) to ethanol (n=1.36), which wave characteristic is LEAST likely to change?
Frequency
371
A Doppler ultrasound device uses the Doppler effect to determine the speed of the blood traveling through a vessel. The tech is holding the probe at a right angle to the direction of blood flow. Assuming the actual flow is 10 cm/s, what frequency would the ultrasound device measure for sound waves bouncing off the blood? (Note: frequency of ultrasound wave emitted: 20 MHz; assume human tissue is equivalent to water; speed of ultrasound in tissue: 1500 m/s)
20.00 MHz
372
What is the equation for wavelength in an open pipe:
Lambda = 2L/n
373
If the energy of a photon is 2 × 10-20 J and Planck’s constant is equal to 6.62 × 10-34 m2⋅kg/s, the photon’s wavelength is:
E = hf; E = hc/lambda -> wavelength = 10 x 10^-6 m
374
In regard to total internal reflection, the critical angle can be expressed using which equation:
c' = sin^-1 (n2/n1)
375
James was recently diagnosed with myopia, a condition in which the lens of the eye has too much converging power. To correct this situation, James should use:
A concave lens with a negative focal length
376
What is the IR value for a carboxyl O-H group and a C=O bond, respectively?
Broad band at 2500-3300 cm^-1, sharp band at 1730-1750 cm^-1
377
In a gas-liquid chromatography chamber:
The higher the boiling point temperature, the more time the compound will spend in the beginning of the chamber waiting to get volatized
378
The researchers want to use narrow-spectrum LEDs to make their lamp more efficient. Assuming that the energy of a photon absorbed by porfirmer is transferred without loss to oxygen, what wavelength of light should the researchers select?
(9.46 x 10^4 J/mol) / (6.02 x 10^23 mol^-1) = 1.57 x 10^-19 J -> Using E = hf and v = f*lambda, we get lambda = hv/E = (6.6 x 10^-34 J*s)(3 x 10^8 m/s) / (1.5 x 10^-19 J) = 1320 nm
379
What is the voltage generated by an electrochemical cell at equilibrium?
Zero
380
During the ionization of transition metals:
Electrons from 4s subshell orbitals are generally removed before those from 3d subshell orbitals
381
Because pH affects the reaction, a student carefully creates a suitable solvent for the reaction. After bubbling CO2 through the solution, he checks the pH and is surprised to find that it is not the same as the original value. What is the most likely cause for this?
The pH will be more acidic because CO2 will combine with H2O to create carbonic acid
382
Under anaerobic conditions, bacteria can sometimes derive energy from the oxidation of sulfur-containing species. Which of the following can NOT be oxidized by anaerobic bacteria?
SO42- (aq) (the species where sulfur has the highest oxidation number)
383
In NMR, peaks around 5-8.5 ppm are indicative of:
Amide hydrogens
384
Surfactants exert catalytic effects through which of the following mechanisms?
Reducing the activation energy of the reaction
385
What would be suitable to convert TX-100 into an anionic surfactant at physiological pH?
Treatment with KMnO4 (an oxidizing agent)
386
What is GLUT4?
An insulin-regulated glucose transporter found primarily in adipose tissues and striated muscle (skeletal and cardiac)
387
What would be most likely to undergo positive beta decay?
The molecule with the highest proton-to-neutron ratio
388
If a leukemia patient has a hematocrit of 60%, with all other factors held constant, what will be the effect of the volume flow rate of her blood?
It will decrease by a factor of 2
389
A horizontal force of 100 N is applied to a 50-kg box that is accelerating at 1 m/s^2 on a rough, horizontal surface. What is the work done by kinetic friction if the box is moved 4 m?
Fnet = ma = Fapplied - Fk -> (50 kg)(1 m/s^2) = 100 N - Fk -> Fk = 50 N -> W = (50 N)(4 m)(cos 180) = -200 Nm = -200 J
390
Which of the following pairs of solvents would form two separate layers when mixed together in a shaker flask and then allowed to settle?
Water and octane
391
Which of the following statements are true of SiO2?
It is a molecule and a compound
392
Which of these options correctly lists five elements in order of decreasing reactivity with water?
Cs > K > Ca > Mg > Be
393
Write a balanced chemical equation for the single-displacement reaction of chromium (III) nitrate with solid zinc.
2Cr(NO3)3 (aq) + 3Zn (s) -> 3Zn(NO3)2 (aq) + 2Cr (s)
394
The combustion of ethanol forms carbon dioxide and water. If 2 moles of ethanol and 4 moles of oxygen are combined in a combustion reaction, the limiting reagent is:
Oxygen
395
A number of astronauts want to use the swinging of a pendulum on a rover to measure the gravitational force on another planet. If a 1 m pendulum with a 0.1 kg mass at the end oscillates with a period of 0.31 s, what is the approximate acceleration due to gravity at the planet’s surface, in terms of the gravity on Earth (g)?
T = 2pi * sqrt (L/g) -> 0.1pi = 2pi*sqrt(1/x) -> x = 400 m/s^2
396
Two charges in a medium with a dielectric constant e experience an attractive electrostatic force, F. How would this force change if the dielectric constant were increased to 2e and the distance were doubled?
Coulomb's constant k = 1/4pi*e -> force would be 0.125 times the original value
397
What is the IR value for an O-H bond?
Broad peak at 3300 cm^-1
398
What is the IR value for a carboxylic acid?
Peak at 3000 cm^-1
399
What is the IR value for an N-H bond?
Sharp peak at 3300 cm^-1
400
What is the IR value for a C=O bond?
Sharp peak at 1750 cm^-1
401
What is the NMR value for hydrogens on sp3 carbons?
0-3 ppm
402
What is the NMR value for hydrogens on sp2 carbons?
4.6-6.0 ppm
403
What is the NMR value for hydrogens on sp carbons?
2.0-3.0 ppm
404
What is the NMR value for aldehyde hydrogens?
9-10 ppm
405
What is the NMR value for carboxylic acid hydrogens?
10.5-12 ppm
406
What is the NMR value for aromatic hydrogens?
6-8.5 ppm
407
The higher the bond order...
The stronger the bond and higher the vibrational stetching frequency (double bonds = higher stretching frequencies than single bonds)
408
What is the entropy of a pure crystalline substance at 0 K?
Zero
409
Between HF, HCl, HBr, and HI, which would have the smallest effect on the boiling point of water, if each final solution has equal molality?
HF (a weak acid, does not completely dissociate/produce as many particles)
410
What is the relationship between vapor pressure and boiling point?
An inverse relationship
411
If a prism is made of a specialized flint glass with an index of refraction of 1.9, at what angle of incidence on the interior of prism will the light cease to exit the right side of the prism?
n1sintheta = n2sin90 -> theta = n2/n1sin90 -> theta = sin^-1 (0.5) = 30 degrees
412
Between red, yellow, green, and blue, which color has the lowest velocity while passing through a glass prism?
Blue
413
If the human eye has a converging lens, which of the following best describes the image that is formed on the retina for an object that is more than one focal length away from the lens?
The image is real and inverted
414
What represents the wavelengths of maximum sensitivity for the red, green, and blue cones of the human eye?
575, 540, and 435 nm, respectively
415
What is the equation for a dissociation constant, like Ka?
Equation: HA -> H+ + A-
416
How do you calculate pI for diprotic amino acids?
Average of the two pKa values
417
How do you calculate pI for triprotic amino acids?
The average of the two acidic pKa values (for acidic amino acids) or the average of the two basic pKa values (for basic amino acids) - pI = always average of 2 PKA values!
418
What was the pH of the unknown amino acid with [OH-] = 3.6 x 10^-11?
pOH = -log (3.6 x 10-11) = 10.64 -> pH = 14-10.64 = 3.36
419
Suppose that a moderately hard surface such as the hard-packed earth described in the passage is found to decelerate a person making a feet-first landing to a stop in an average of 0.09 seconds. What is the person's deceleration in terms of g (where 1 g = 9.81 m/s2) when falling from a height of two meters?
Vf^2 = Vi^2 + 2ad -> vf^2 = (0 m/s)^2 + 2(10 m/s^2)(2 m) = 40 m^2/s^2 -> a = (0 m/s - 6.4 m/s) / 0.09 s -> 64 m/s^2
420
While playing, a 40-kg child is accidentally pushed directly forward off a ledge, causing him to fall and hit the ground at a 60° angle. If the child has 720 J of kinetic energy at the instant before impact, at what velocity was he pushed? Assume negligible air resistance.
KE = 1/2mv^2 -> 720 J = 1/2 (40 kg)(v^2) -> v = 6 m/s -> vhorizontal = vtotal * cos(60) -> 3 m/s
421
Given the relationship between force per cross-sectional area and break frequency described in the passage, it is reasonable to expect:
Those runners with the briefest interval of ground contact per step to be more liable to breaks
422
What is the rate of effusion?
The SQUARE ROOT of the ratio of the molar masses
423
What is the function of a ribonuclease in E. coli?
It cleaves RNA
424
What is the latent heat of fusion?
The amount of energy needed for the fusion (melting) of 1 unit of mass
425
In what amino acids does phosphorylation occur?
Serine (usually), threonine and tyrosine (eukaryotes), and histidine (prokaryotes)
426
An experimenter proposed employing a material with an index of refraction strongly dependent upon the wavelength of transmitted light for use in an objective lens. How would the use of such a material impact the performance of a microscope?
Images formed by the eyepiece from transmitted light containing multiple wavelengths will be unfocused
427
In order for the image produced by the eyepiece (converging lens) to be erect, where must the image focused by the objective lens fall?
At a distance from the eyepiece smaller than the eyepiece's focal length
428
For questions that ask for the number of stereoisomers:
Draw out the stereoisomers
429
Which is a stronger base: sodium carbonate or methyl acetate?
Methyl acetate
430
In an isolated system, entropy is maximized when:
The system is at equilibrium and the system is unable to perform work
431
To determine which hydrogen bond has the lowest bond dissociation enthalpy:
You look for the least electronegative atom
432
An organic synthesist seeks to identify an efficient stereoselective reagent with which to produce the enantiomer of the biologically active sphingosine molecule pictured in the passage. Which of the following would be the most logical choice to try?
Diethyl tartrate; tert-butoxide, DMSO, and propanol are achiral
433
The conversion of dihydrofolate to THF occurs via the enzymatic addition of a hydride to dihydrofolate. The enzyme that catalyzes this reaction is an example of a:
Reductase
434
A strong wind lifts a 2-g leaf and propels it 3 m along a spiral path to reach a height of 2 m above the ground. What is the work done by gravity throughout this process?
U = mgh = (0.002 kg)(10 m/s^2)(2 m) = 0.04 J
435
p-Nitrophenol has a pKa of 7.16. Which of the following most accurately approximates the ratio of the conjugate base to p-nitrophenol in the pH 11 stop solution?
pH = pKa + log (conjugate base) / (acid) -> 11 = 7 + log (conjugate base) / (acid) = 10^4 = 10,000:1
436
What is acidity determined by?
The stability of the conjugate base -> benzene backbone and nitrogen are sp2 hybridized, creating a plane of delocalized pi electrons (the more electronegative across, the more acidic; the bigger the atom on the way down, the more acidic)
437
Given a 5.0-ampere current running for a total of four hours and ten minutes, what will be the amount of hydrogen gas produced in an electrolysis reaction? (Faraday’s constant = 96,485 C per mole of electrons)
(5 C/s)(15,000 s) = 75,000 C -> (75,000 C) / (96,485 C/mol) ~ 0.8 moles -> 0.4 moles of hydrogen gas
438
In an electrolytic cell, electrons flow into the electrolytic solution from:
The negatively-charged cathode, in order to allow reduction
439
To have a faster rate of effusion:
A compound should have a low molecular weight
440
When thinking logically about atomic/ionic radius:
The greater number of protons, the more attraction the electrons will have to the nucleus
441
What are the units for zero order, first order, and second order reactions?
mol/s, 1/s , and 1/mol*s
442
What is the difference between mass number and atomic number?
Atomic number = number of protons, mass number = number of protons + number of neutrons
443
What is the difference between ionization energy and electron affinity?
Ionization energy = energy required for an atom to lose an e- (to become an ion), electron affinity = energy released when an atom to gain an e-
444
What is reactivity with water based on?
Ionization energy
445
What is the difference between the Pauli exclusion principle and Hund's rule?
Pauli exclusion rule = no two electrons can have the same exact quantum numbers; Hund's rule = each orbital must contain one electron before any electrons are paired
446
What is the Bohr model?
Electrons occupy only certain orbits around the nucleus, those orbits are stable and are called "stationary" orbits, and each orbit has an energy associated with it
447
What are the different types of spectra?
Lyman series (UV rays) -> n = 1; Balmer series (visible rays) -> n = 2; Paschen (infrared rays) -> n = 3
448
What accurately describes the behavior of photoelectrons?
A photoelectron's energy cannot equal the energy of the incident photon, and the intensity of incident light is unrelated to the energy of an ejected photoelectron
449
To calculate limiting reagents:
USE MOLES AND WRITE OUT A BALANCED EQUATION
450
What is perchloric acid, chloric acid, and chlorous acid?
Perchloric = HClO4, chloric = HClO3, chlorous = HClO2
451
What is normality?
Number of equivalent weights / liters of solution
452
How does the size of an ion relate to its ability to be a surfactant?
Larger cation = higher propensity for an ionic bond as opposed to a covalent bond (higher efficiency for ionic bonding = higher efficacy as a surfactant)
453
Which weighs more: fat or muscle?
Muscle
454
What is the buoyant force equation?
Fb = density of body * volume of displaced body * g
455
What is the most likely reason that the subjects were required to exhale completely prior to immersion in the water tank?
Air in the lungs decreases the apparent weight of the body in water and increases the percent fat estimation (increases buoyancy)
456
What is the force of a magnetic field?
F = qvB sin theta (if the charge is motionless, then v = 0, so F = 0)
457
What is an amphiprotic ion?
Can act as an acid or a base
458
What are some true statements about blood flow?
The blood velocity and pressure are higher in arteries than in capillaries, blood vessels do NOT follow Bernoulli's principle if viscosity of blood is taken into account, for an incompressible fluid undergoing laminar flow through a pipe with both narrow and wide sections, the fluid velocity is higher in the narrow areas than in wider areas
459
What aspect of sound changes when going into a different medium?
Wavelength
460
What is the equation for osmotic pressure?
Osmotic pressure = molarity * r(8.314) * temperature
461
An object weighs 150 g in air, 75 g when fully submerged in water and 60 g when fully submerged in an unknown fluid. What can be concluded about the specific gravity of the unknown fluid and the order of layers when water is mixed with the unknown fluid (assuming the unknown fluid is immiscible in water)?
The specific gravity of the unknown fluid is 1.2, and water will be the top layer -> mass of displaced water = 150-75 = 75 g -> volume of displaced fluid = 75 cm^3 -> 150 g - 60 g = 90 g -> 90 g/75 cm^3 = 1.2 g/cm^2
462
What molecules can perform an antioxidant function in vivo?
Ubiquinone, vitamin E, NADH
463
If the transducer measures a wavelength of 616 μm and a time to return of 104 μs for the waves hitting the uterus, approximately how far from the skin is the uterus?
2.5 MHz = 2.5 x 10^6 Hz -> wavelength = 6 x 10^-4 m -> v = lambda * f = (2.5 x 10^6 Hz)(6 x 10^-4 m) = 15 x 10^2 m/s -> d = (15 x 10^2 m/s)(104 x 10^-6 sec) = 0.15 m = 15 cm
464
What is the equation for a period of a spring?
T = 2pi * sqrt (m/k)
465
A precipitate forms when:
The ion product (Q) for a compound exceeds the Ksp for the same compound
466
What is Ksp equal to:
Concentration of products / concentration of reactants
467
Under some circumstances, the Clark cell overestimates the dissolved oxygen content of blood. Which of the following gives the most reasonable explanation for this?
Other membrane-permeable gases are reduced in an analogous manner to oxygen
468
What is the kinematics equation without x?
v = v0 + at
469
What is the kinematics equation without a?
Delta x = (v + v0 / 2) t
470
What is the kinematics equation without v?
Delta x = v0t + 1/2at^2
471
What is the kinematics equation without t?
v^2 = v0^2 + 2a*delta x
472
Absorption of ultraviolet light by organic molecules always results in what process?
Excitation of bound electrons (UV-Vis spectroscopy = measures excitation; infrared spectroscopy = bond stretching/vibration)
473
In column chromatography:
Whichever compounds follow the stationary phase will have a longer elution time
474
Where does the phosphoryl transfer from kinases come from?
Gamma P-ATP
475
When serine and threonine are phosphorylated:
They will have the same charge as glutamic/aspartic acid
476
What are storage lipids?
Triacylglycerols
477
What is the role of a solid-state catalyst?
It increases the amount of product produced per unit time
478
What statements describe a DNA double helix?
Sugar phosphate backbone = exterior, hydrophobic core = interior
479
Can you add protons to something?
NO
480
What kind of image is formed by a diverging lens that is over 2* focal length?
Virtual and reduced
481
Protein secondary structure is characterized by the pattern of hydrogen bonds between:
Backbone amide protons and carbonyl oxygens
482
Where does the image end up for a converging (convex) lens?
Greater than 2f = real, inverted, reduced; at 2f = real, inverted, same size; between 2f and f = real, inverted, enlarged; at f = no image; less than f = virtual, upright, enlarged
483
Where does the image end up for a diverging (concave) lens?
Pretty much always virtual, upright, and diminshed
484
What is the result of electron capture?
Loses one electron, atomic number decreases by 1
485
What is the most stable steric conformation?
Equatorial
486
What is the most stable/least stable conformation about a single bond?
Anti staggered/periplanar eclipsed
487
What are absolute and relative configurations?
Absolute = within a single bond (R/S); relative = compared to another molecule (L/D); E-Z system = double bonds
488
What is the law of gravitation?
F = Gm1m2/r^2
489
What is Pascal's law?
If you apply pressure on a liquid, the pressure is transmitted equally to all parts of the liquid (F1/A1 = F2/A2)
490
What is the concept of turbulent flow at high velocities?
Low velocity = laminar flow; high velocity = turbulent flow, forms eddies
491
What is Coulomb's law?
F = kq1q2/r^2 (if the charges have the same sign, the force is repulsive; if the charges have different signs, the force is attracive)
492
What is the equation for magnetism?
F = qvB sin theta (theta = angle between charge velocity and magnetic field)
493
What is Dalton's law?
Total pressure = sum of partial pressures
494
What are lead storage batteries?
Voltaic cell when fully charged -> Pb anode and PbO2 cathode
495
What are nickel cadmium batteries?
Rechargable cells, Cd (s) (anode), nickel (III) oxide-hydroxide (cathode) conneted by KOH
496
Why is isoelectric focusing weird?
The amino acids migrate towards a similar charge (positive -> cathode)
497
What is x-ray diffraction?
X-rays diffracting on a crystal
498
What is the diffraction equation?
dsintheta = m*lambda (d = distance between the slits), for single-slit -> asin = m*lambda (a = width of slit)
499
What is diffraction grating?
A slab with many slits close together
500
What is a red shift?
In Doppler effect, frequency decreases (when source and observer are moving away from each other)
501
What is a blue shift?
In Doppler effect, frequency increases (when source and observer are moving towards each other)
502
What is dispersion?
A change in the index of refraction with wavelength (blue lights refracts more than red light in a prism)
503
What is lens strength?
1/focal length
504
What is magnification?
Height of image/height of object
505
What are the requirements of a hydrogen bond?
A hydrogen bond donor (a molecule with a hydrogen bonded to a highly electronegative atom) and a hydrogen bond acceptor (electronegative atom)
506
When the caraway seed oil is heated, which of the two components will most likely distill first?
Limonene (less polar = lower boiling point), distills first
507
What is the function of the ebulliator?
Prevent superheating of the liquid to be distilled
508
Which would increase the degree of separation between compounds in fractional distillation?
Heating the distillation flask at a slower rate
509
Plus and minus enantiomers differ in the orientations of the substituents around which carbon?
Stereogenic center
510
If a leak develops in the vacuum distillation apparatus, the boiling points of the two components of caraway seed oil will:
Both increase
511
Between two compounds, which one would be more soluble in water?
The one that is more capable of forming hydrogen bonds
512
Alcohols generally require acid catalysis in order to undergo substitution by nucleophiles. The acid catalyst enhances the reaction by:
Creating a better leaving group
513
What is true of an ionic compound?
It conducts electricity
514
Which of the following properties is associated with the existence of glycine as a dipolar ion in aqueous solution?
High dipole moment
515
The alpha and beta derivatives of a sugar differ at:
C1
516
Rates of chemical reactions always increase with:
Increasing temperatures
517
How much NaOH is needed to completely saponify a triacylglycerol?
Three equivalents, because one OH- ion is required to saponify each of the three fatty acid groups
518
What most accurately describes the solubility properties of fatty acid salts?
They can partially dissolve in both polar and nonpolar media
519
Why is N2 very unreactive?
The great strength of the N-N triple bond
520
The reactivity of a metal depends on its:
Ionization potential
521
The ionization constant of a weak acid would be:
Much less than 1
522
In the Bohr model of the atom, radiation is emitted whenever electrons:
Move to orbits of lower energy
523
What is a general characteristic shared by all catalysts?
They increase the reaction rate but do not change the Keq of a reversible reaction
524
Net force, and therefore acceleration, acting on a box on an incline plane increases with:
increasing angle to the horizontal
525
The gravitational force equation says that:
gravitation between two bodies is proportional to the product of their masses
526
What is an equation that relates mass to heat of fusion?
Q = m * Hf (heat = mass * heat of fusion)
527
The vertical pipe with the highest water level will have:
The greatest cross-sectional area
528
What is the continuity equation?
Q1 = V1A1 = V2A2
529
Why do radioactive isotopes exhibit the same chemical behavior as the stable isotopes?
Atomic number
530
What are units of electric field?
Volts/meter = newton/coulomb
531
Destructive interference occurs in photodiode detectors when direct and scattered light rays take paths to the photocell that differ in phase by:
180 degrees
532
The tone with the shortest period has the:
Shortest wavelength
533
What is the relationship between speed of the transmitter away from the receiver and the increase in wavelength?
Linear positive
534
The increase in distance between radio wavese causes:
A lengthened wavelength (increase in Doppler effect)
535
An astronaut on Earth notes that in her soft drink an ice cube floats with 9/10 of its volume submerged. If she were instead in a lunar module parked on the Moon where the gravitation force is 1/6 that of Earth, the ice in the same soft drink would float:
9/10 submerged (weight and buoyant force are proportional to g)
536
A student has a thin copper beaker containing 100 g of a pure metal in the solid state. The metal is at 215°C, its exact melting temperature. If the student lights a Bunsen burner and holds it for a fraction of a second under the beaker, what will happen to the metal?
A small amount of the metal will turn to liquid, with the temperature remaining the same
537
An electron is ejected from the cathode by a photon with an energy slightly greater than the work function of the cathode. How will the final kinetic energy of the electron upon reaching the anode compare to its initial potential energy immediately after it has been ejected?
It will be approximately equal (if the photon energy is near the work function, this means that little kinetic energy will be left for the electron)
538
When the number of photons incident on the cathode with energies above the value of the work function increases, which of the following quantities also increases?
The number of electrons ejected
539
Which of the following best describes the movement of an electron after it is ejected from the cathode?
It accelerates towards the anode
540
Which of the following occurs when electrons are ejected from the cathode?
Current flows through the circuit
541
If the speed of the charged particle described in the passage is increased by a factor of 2, the electrical force on the particle will:
Remain the same
542
What are two equations for force?
F = ma; F = qE
543
The maximum electrical potential energy occurs at:
Maximum displacement
544
Which action requires a larger absolute value of work: lifting the weight from A to B with constant speed, or lowering the weight from B to A with the same constant speed?
Equal absolute value work in both actions
545
What is the conservation of energy equation?
KE = PE
546
The focal length only depends on:
The radius of curvature
547
Visible light travels more slowly through an optically dense medium than through a vacuum. A possible explanation for this could be that the light:
Is absorbed and re-emitted by the atomic structure of the optically dense medium
548
When switch S is closed to the left, charge begins to accumulate on the capacitor. Charge cannot accumulate indefinitely because:
Successive charges brought to the plates are repelled by charges accumulated earlier (two plates of a capacitor collect charges of opposite sign)
549
Which of the following describes the direction of motion of alpha, beta, and gamma rays in the presence of an external magnetic field?
Gammar rays travel straight; alpha and beta rays are bent in opposite directions
550
Work is the product of:
Force x distance
551
An artery is constricted at one location to 1/2 its normal cross-sectional area. How does the speed of blood past the constriction compare to the speed of blood flow in the rest of the artery?
It is 2 times as fast
552
A stronger magnet would increase the:
Voltage
553
Volume flow rate is equal to:
Product of blood speed and artery cross-sectional area
554
What is the round-trip time for a ball thrown vertically?
t = 2v/g
555
Which of the following statements best explains why the intensity of sound heard is less when a wall is placed between a source of sound and the listener?
Part of the sound energy is reflected by the solid
556
What is the coefficient of friction?
Frictional force / normal force
557
What is the spacing between adjacent nodes in a standing-wave pattern?
Lambda / 2
558
What is resistance equal to?
Resistivity * Length/Area
559
When 7/4Be undergoes radioactive decay by electron capture (a form of β+ decay), the resulting nucleus is:
7/3Li
560
What is the maximum number of electrons allowed in a single atomic energy level in terms of the principal quantum number n?
2n^2
561
What is the maximum number of electrons that can fit in a subshell?
4l + 2
562
Metals are often used for making wires that conduct electricity. Which of the following properties of metals explains why?
Metals have valence electrons that can move freely
563
What is an aspect of mass spectroscopy?
The velocity of ions depends on the ion mass-to-charge ratio
564
Why do liposomes fluoresce during size-exclusion chromatography?
Fluorescent dye was trapped inside
565
What is the bond that links monosaccharides together in an oligosaccharide?
A glycoside bond
566
When performing experiments to measure the kcat of an enzyme, the substrate concentration should be:
Saturating
567
When experiments are performed on enzymes that display traditional Michaelis–Menten kinetics, what shape does the graph of V0 versus substrate concentration [S] have?
A hyperbolic dependence on [S]
568
A protein contains four disulfide bonds. In order to break these bonds researchers added a minimum of:
4 moles of NADH for each mole of protein
569
A protein with which properties will most likely have the largest negative net charge at pH 7?
A protein that binds to an anion-exchange column at pH 7 and requires a high concentration of NaCl for elution
570
What is Tm?
When half of the molecules are denatured
571
Which of the four DNA bases contains the largest number of hydrogen bond acceptors when involved in a Watson–Crick base pair?
Cytosine
572
Thermal denaturation experiments can be used to follow the transition of double-stranded DNA into single-stranded DNA. Which of the following parameters affects the Tm of dsDNA in this experiment?
pH of solution, ionic strength of solution, and length of DNA strands
573
The side chain of which amino acid can form a bond that is similar to a peptide bond?
Lysine (isopeptide bonds)
574
What describes the properties of maltose?
It is a reducing disaccharide in which only one anomeric carbon is involved in the glycosidic bond
575
Which of the following peptides is most likely to form a covalently bonded dimer?
ANY PEPTIDE WITH CYTOSINE
576
The relative thermodynamic stability of isomeric organic compounds can be inferred from which of the following types of experimental data?
Heats of combustion (amount of heat released when a gram of a substance burned)
577
What is chelation?
2+ bonds to a single metal ion
578
What is the mass of water?
18 atomic mass units
579
What is the basic unit of a porphyrin?
A pyrrole ring
580
A common column material used in size-exclusion chromatography is dextran, a polysaccharide of glucose. Which type of interaction most likely occurs between proteins and the dextran column material?
Hydrogen bonding
581
Which of the following properties of a 2.3 MHz ultrasound wave remains unchanged as it passes into human tissues?
The frequency of a wave is not affected by the medium through which it propagates
582
In solubility equations (Ksp):
It is just looking at the concentrations of the reactants
583
When a weak acid (HA) is titrated with sodium hydroxide in the presence of an indicator (HIn), the pH at which a color change is observed depends on the:
pKa of HIn
584
Which of the following statements best characterizes a material that is a good insulator but a poor conductor?
Electrons in the material cannot easily move from one atom to another
585
A reaction is designed to produce ammonia from the gas phase equilibrium of nitrogen and hydrogen. Introducing a catalyst into the system will cause the amount of ammonia at equilibrium:
To remain the same (lowers activation energy, but does not increase amount of product formed)
586
Which of the following substances is most likely to be more soluble in 1.0 M HCl than in 1.0 M NaOH?
Pb(OH)2
587
An electrochemical cell is designed to produce pure copper from CuSO4. An increase in which of the following cell conditions will most effectively increase the rate at which pure copper is produced?
The concentration of SO42+ (aq)
588
In which of the following does sound travel most rapidly?
Iron (20 degrees C) - the speed of sound is greatest by far in a solid because of the strong intermolecular bonds and close proximity of the molecules
589
In a nearsighted individual, the image of a distant object is focused:
In front of the retina, requiring diverging lens correction
590
A battery in a circuit has an electromotive force given by ℰ and an internal resistance of r. The battery provides a current i to the circuit. What is the terminal voltage of the battery?
Voltage = electromotive force - current*resistance
591
A glass fiber carries a light digital signal long distances with a minimum loss of amplitude. What optical property of glass allows this phenomenon?
Reflection AKA total internal reflection
592
A 15.0-eV photon collides with and ionizes a hydrogen atom. If the atom was originally in the ground state (ionization potential =13.6 eV), what is the kinetic energy of the ejected electron?
15.0 - 13.6 = 1.4 eV
593
What is Archimedes' principle?
The buoyant force of an object immersed in a fluid is equal to the weight of the fluid displaced by the object
594
Suppose that a stream of fluid flows steadily through a horizontal pipe of varying cross-sectional diameter. Neglecting viscosity, where is the fluid pressure greatest?
Maximum diameter -> low KE -> high pressure
595
The properties of sound waves allow them to propagate through:
Solids, liquids, and gases only
596
In a healthy person standing at rest, a comparison of arterial blood pressure measured in the arm with that measured in the leg shows that the pressure in the leg is:
Greater, because the column of blood between the arm and the leg has a hydrostatic pressure
597
Electric power for transmission over long distances is “stepped up” to a very high voltage in order:
To cut down the heat loss in the transmission wires
598
If ocean waves strike the shore every 3.0 s and the horizontal distance between adjacent crests and troughs is 1.0 m, what is the average speed of the waves?
Wave speed = 2 m / 3 s = 0.67 m/s
599
An unknown solid weighs 31.6 N. When submerged in water, its apparent weight is 19.8 N. What is the specific gravity of the unknown sample?
31.6 / (31.6 - 19.8) = 2.68
600
What is stronger: LiAlH4 or NaBH4?
LiAlH4
601
What is mCPBA?
An oxidizing agent
602
Why won't something be able to undergo keto-enol tautomerization?
No alpha hydrogens
603
In NMR:
Something that is more electronegative (CHF3) would be more downfield than something that is less electronegative (CH3Br)
604
What reagant will cause the greatest oxidation of a primary alcohol?
KMnO4
605
What is another work equation?
W = Delta U = mgh
606
What is the absolute pressure equation?
P = P0 + pgz
607
What correctly shows the features of ammeters and voltmeters?
Ammeters: negligible resistance, connected in series; voltmeters: infinite resistance, connected in parallel
608
At what point in the circuit does an electron have the greatest electric potential energy?
When leaving the battery (before energy has been converted to KE or lost as heat)
609
What is true about sound waves?
Move more quickly through solids than through gases, cannot propagate through a vacuum
610
What are some examples of solutions?
Water and ethanol, vinegar, gasoline
611
When binding excess H+ ions from the blood plasma, hemoglobin molecules act as:
Bronsted-Lowry bases and buffers
612
Which point on a titration curve for a diprotic acid corresponds to the optimal buffering capacity for that system?
Half-equivalence point
613
When looking at normality and gram equivalent weight:
If something has a molecular weight of 90 g/mol and a normality of 2 N, its gram equivalent weight = 45 grams
614
When it comes to colligative properties (vapor pressure, boiling point, freezing point, osmotic pressure):
The more solute in a solution, the greater the effect
615
In the balanced reaction H2CO3 -> HCO3- + H+, adding sodium bicarbonate would do what:
Adds bicarbonate ions to the solution, causing the equilibrium to shift left
616
What is the difference between hypochlorous acid, chloric acid, and perchloric acid?
Hypochlorous acid = HOCl, chloric acid = HClO3, perchloric acid = HClO4
617
What is an Arrhenius acid?
A substance that dissociates in water to form hydrogen ions or protons
618
A scientist mixes (2S)-2-bromobutane in water. The resulting compound most likely:
Has no optical activity
619
In an IR spectrum, why is it impossible to see any light absorbance in homogeneous diatomic molecules?
There will be no record of changes in dipole moment
620
In NMR spectroscopy, is it possible for a molecule to have a negative chemical shift?
Yes, because chemical shift is standardized by convention using TMS and not an absolute value
621
What does an IR spectrum value of a sharp peak at 3300 cm-1 mean?
N-H bonds
622
What is a difference between UV and IR spectroscopy?
IR spectroscopy is better at precise identification of molecules than UV spectroscopy (other differences = UV light has more energy than IR light; IR = absorption of infrared lihgt; UV = absorption of UV light)
623
As the number of conjugated systems increases:
The distance between the HOMO and LUMO decreases -> smaller energy = larger wavelength
624
What is wavenumber?
The inverse of wavelength
625
PCC cannot oxidize:
Aldehydes
626
What are base units in the SI system?
Seconds and kilograms
627
Consider a positively-charged particle that is experiencing a force due to an external electric field. Which of the following are conserved for the particle?
Total energy
628
The moon's orbit around the Earth is approximately circular. How much work is done on the moon by the force of gravity when the moon completes half an orbit around the Earth? (Note: radius of moon's orbit: 3.85 × 105 m; mass of Earth: 6 × 1024 kg; mass of moon: 7.3 × 1022 kg; moon orbital time: 27 days)
0 J
629
A ball attached to a string on a tabletop is swung in a circle with a velocity of v. The string is threaded through a small hole in the table such that it can be pulled on to be shortened. If the string is loosened and allowed to extend to three times its original length, how will the ball’s velocity change?
The velocity of the ball will decrease to one-third of its previous value
630
A metal box with a glass bottom slides down a steep incline. The incline can be assumed to be frictionless, and no air resistance acts on the box as it slides. However, a substantial amount of gravitational potential energy is converted to kinetic energy. Which of the following statements about this process is true?
Total mechanical energy and total energy are conserved
631
What are the SI units for power?
Watts = 1 J/s
632
The intermolecular forces that exist among the molecules of NH3 gas are:
Both dipole-dipole and London dispersion forces
633
What is the equation for Kb?
Kb = [products] / [reactants] -> do not include liquids or solids, also applies for Ka
634
Is CH4 polar or nonpolar?
Nonpolar
635
Noble gases have zero:
Electron affinity
636
Wavelength is inversely proportional to:
Energy of a photon
637
A triple bond has:
1 sigma bond and 2 pi bonds
638
The saturated fatty acid that is the most soluble in water:
Has the shortest alkyl chain
639
One company sells a defibrillator for home use that uses a 9-volt DC battery. The battery is rated at 4.2 A•hr (amp•hour). Roughly how much charge can the battery deliver?
Current = charge/time -> charge = current *time -> 4.2 A * 3600 s = 15,000 C
640
What reagant, when mixed with acetone, CrO3, and aqueous H2SO4, will produce butanoic acid?
1-Butanol
641
What nucleophile would be LEAST capable of undergoing a nucleophilic substitution reaction with acetone?
A tertiary amine (trimethylamine)
642
Which of the following describes the bond that is broken and the products that are formed during a retro-aldol reaction?
Bond between alpha and beta carbon of carbonyl; aldehydes and/or ketones
643
Ubiquinone, as known as CoQ10, is an important cofactor necessary for transport of electrons down the electron transport chain during aerobic respiration. In complex I, two electrons from NADH are transferred to CoQ10. Which of the following correctly describes the redox reaction that occurs in complex I?
Ubiquinone converts to a ubiquinol
644
A chemist determines that the alpha hydrogens in esters are less acidic than the alpha hydrogens in ketones in general. Which of the following is the most reasonable explanation for this phenomenon?
The resonance structures for the ester enolate are relatively unstable due to the alkoxy oxygen
645
What are tautomers?
Constitutional isomers
646
Which of the following lists molecules in order of increasing electrophilicity of the carbonyl carbon?
Acetamide < acetone < acetyl chloride
647
Among the carboxylic acid derivatives, anhydrides are more reactive than amides. Which of the following best explains this phenomenon?
Anhydrides have three electron withdrawing oxygens that increases electrophilicity
648
Why is LiAlH4 capable of reducing carboxylic acids?
H– from LiAlH4 is a strong enough nucleophile to push electrons from the π bond in the carbonyl to the oxygen atom
649
Saponification of a fatty acid leads to the formation of:
A carboxylic acid salt and water
650
The material that has the greatest density would have the slowest:
Speed of sound waves
651
What is the sound equation?
dB = 10 log I/I0
652
For sound:
v = f * lambda
653
As it passes through a single polarizing filter, the intensity of unpolarized light will be:
Cut in half
654
Which of the following colors of light will bend the least when moving from a vacuum to a glass prism?
Red light = longest wavelength = smallest index of refraction
655
Which changes are experienced by visible light as it moves from Medium 1 (n = 1.16) to Medium 2 (n = 1.68)?
Wavelength decreases while frequency remains constant
656
For total internal reflection to occur:
Light must be traveling from a medium with a high index of refraction to one with a low index of refraction, and there should be a large difference between the indices of refraction
657
A mirror with a focal length of +5 m could be described as:
Concave and converging
658
When an infrared ray transitions from air (n = 1) to ethanol (n = 1.36), which wave characteristic is LEAST likely to change?
Frequency
659
The function -cos(t) is how many degrees out of phase with sin(t)?
-270 degrees
660
What is the equation for specific gravity?
Density of object / density of H2O
661
A particular circuit contains only a single battery and two resistors. If these resistors are connected in parallel:
The voltage across them is the same, but the current that passes through may differ (Kirchoff's Loop Rule)
662
A circular segment of gold wire is positioned in an external magnetic field of strength B that points out of the page. If the strength of the field is increased to 2B, what will happen to the wire?
It will experience a clockwise current
663
Which bond would be expected to have a high vibrational stretching frequency in the infrared spectrum?
C=O (higher bond order -> stronger the bond -> higher the vibrational stretching frequency)
664
The bonds formed between 2,3-bisphosphoglyceric acid forms and hemoglobin (disulfide bridges) are most similar to:
Ionic bonds
665
The bond formed between hemoglobin and nitric oxide is best categorized as:
Nonpolar covalent
666
What properties of wax esters explain their ability to maintain the moisture of the eye tissue?
Non-polar carbon chain
667
If a gas chromatograph is damaged such that it no longer reaches the max temperature required to analyze the unknown sample, what is the most effective way to fix this issue?
Lower the pressure within the chromatograph
668
What are mass number and atomic number?
Mass number = protons + neutrons; atomic number = protons
669
What is related to reactivity with water?
Ionization energy
670
What is the Aufbau principle?
Electrons fill orbitals in order of increasing energy
671
The Bohr model of the atom hypothesizes that electrons orbit the nucleus at discrete distances. Additionally, it states that these distances may also relate to the energy level of the associated orbital. Which actual observation lent support to this hypothesis?
Atoms were shown to emit electromagnetic waves at specific frequencies proportional to the energy difference between the orbits
672
What describes the behavior of photoelectrons?
A photoelectron’s energy cannot equal the energy of the incident photon, and the intensity of incident light is unrelated to the energy of an ejected photoelectron
673
What is percent yield?
Actual yield / theoretical yield x 100%
674
A precipitate forms when:
The ion product (Q) was greater than Ksp
675
Ksp only responds to:
Changes in temperature
676
What represents the auto-ionization of water?
2H2O (l) -> H3O+ (aq) + OH- (aq)
677
Of the following choices, the most effective buffer solution could be formed by mixing equal moles of:
Hydrofluoric acid and potassium fluoride (a weak acid and its conjugate base)
678
For electrolytic/galvanic cells:
Electrolytic = ALL ABOUT MAKING E NEGATIVE; galvanic = ALL ABOUT MAKING E POSITIVE
679
Nickel-cadmium (NiCd) batteries are rechargeable cells used in products ranging from remote-control toys to airplanes. An NiCd battery in the process of discharging is most analogous to:
A galvanic cell
680
Why is carbon monoxide a polar molecule, even though carbon dioxide is nonpolar?
Carbon dioxide has a symmetrical structure
681
Which of the following molecules has the highest predicted melting point?
Ionic bonds/salts
682
Which of the following can exert the strongest intermolecular forces on like particles?
Acetic bond (because of the -OH group)
683
The formula ΔTb = Kbmi can be used to calculate boiling point elevation, a colligative property. Which of the following are possible units for Kb?
(degrees C * kg) / mol
684
What are the formulas for elastic work and elastic force, respectively?
W = 1/2kx^2; F = kx
685
What is an equation for power at constant speed?
P = F * v
686
The 32P label was generated from naturally occurring phosphorous by:
Adding a neutron to the nucleus
687
Human speech is generated in the vocal cords as the lungs push air past them. What property of the vocal cords is changed so that the frequency of sound can be altered?
Tension
688
For galvanic/electrolytic cells:
If it is a salt bridge = galvanic; if there is a battery involved = electrolytic
689
For indicators:
ROYGBIV goes from acidic to basic
690
What is a titration?
Analytical technique to figure out an unknown concentration of a known solution
691
What are the three types of lipids?
Storage (HYDROLYZABLE,triacyl glycerols, free fatty acids = energy storage); structural (HYDROLYZABLE,phospholipids, phosphatids, sphingolipids aka neurons, waxes aka barrier to water); signals/cofactors (NON-HYDROLYZABLE,fat-soluble vitamins, steroids, prostaglandins which lower BP, lower platelet aggregation, are affected by NSAIDs)
