Chem/Phys Flashcards
(98 cards)
1
Q
Pouseuille’s Equation (Flow)
A
Flow = ΔPπr^4 / 8Lη
η = Viscosity
Radius to the 4th power
2
Q
Surface Tension ______ As temperature Rises
A
Decreases
3
Q
Good Nucleophiles are
A
Electron Rich
Watch for stearic hindrance
4
Q
Relative reactivities of Carboxylic Acid Derivatives
A
acyl halides > anhydrides > esters and acids > amides.
5
Q
Thioether group
A
C-S-C
6
Q
Amide
A
=O bonded to N
7
Q
Imine
A
C=N
8
Q
Alpha Decay
A
Emit an alpha particle, He nucleus
9
Q
Beta+ Decay
A
Positron emission - Converts a proton to a neutron and emits a positron
10
Q
Beta- Decay
A
Converts neutron to proton, emits an electron
11
Q
Charged species always _______ polar compared to uncharged
A
more
12
Q
Field Strength Equation
A
β = µI/2r I = current r = radius µ = permeability of space constant
13
Q
Colors with shorter wavelengths will refract (More/Less)
A
More, violet light is refracted and slowed down the most
14
Q
Deuterium has how many neutrons
A
1.
1 proton and 1 neutron
15
Q
An ice cube floating partially submerged – Melts – Does height of water in glass rise or lower
A
It doesn’t move, since objects displace their weight in water!
16
Q
Why must potassium be stored in an inert gas?
A
It has a low first ionization energy, so it wants to lose it’s electron really badly and it will react violently with atmosphere.
17
Q
Gram equivalent weight
A
Mass per acidic proton
= (Total mass) / (#protons)
18
Q
Charge of 1 mole of electrons
A
96485 Coulombs
19
Q
Chalcogens
A
Left of halogens - oxygen sulfur etc
20
Q
ΔG = ΔH – TΔS
What are the letters
A
G = Free energy H = Enthalpy S = Entropy For spontaneity: ∆G < 0
21
Q
If heat added to water, will pH change?
A
Yes! Since H+ and OH- will dissociate more, and pH and pOH will both go down!
pKw only 14 at STP
22
Q
When is fractional distillation used?
A
When compounds boiling points are within 25 degrees Celsius
23
Q
Which of the following procedures would be best for extracting methanal from an aqueous solution?
A
Four successive extractions with 18.75 mL of ether
SERIAL EXTRACTIONS ALWAYS MORE EFFECTIVE THAN SINGLE EXTRACTIONS
24
Q
Why can rotation of light not be used to separate?
A
It is a method of analysis, not separation
25
Newton's third law applied: Book on table
Earth experiences a pull of mg on from the book, as the book experiences a pull of mg from the earth.
26
Is Diatomic nitrogen inert?
Yes it can be used to prevent unwanted side reactions
27
O2 --> H2O has a higher/lower standard voltage change than other components of ETC
Higher, since it is the final acceptor, so it needs a more positive potential than all other steps.
28
Energy in Oxidative phosphorylation is either....
Used to pump protons or lost as heat
29
Ethers -OR (-OCH3) are electron (donating/withdrawing)
Donating!
Carboxylic acids are withdrawing
if attached by O-C or N-H or C-H it is donating, if attached by C-O or N-O it is withdrawing
30
Rules for ∆G = ∆H - T∆S
For ∆S sign look at whether the reactants or products are more or less disordered. Positive ∆S = Decrease in organization
31
Imide
R-(C=O)-(N-R")-(C=O)-R'
32
Homotropic regulation
Account for cooperativity!
| Sigmoidal shape in Hb binding curve for oxygen
33
Relative humidity
Varies in altitude by the amount of water that the air can hold at that altitude
50% at high altitude is much less than 50% at sea level
34
How to choose pKa of indicator
If you are titrating with strong base --> pKa is >7
" " Strong acid --> pKa is <7
Will be +/- 1 pH from the endpoint
35
Positive control
Not exposed to experimental treatment but to some other treatment which produces the expected effect
(to make sure it can happen)
36
Negative control
A control group that is not exposed to experimental treatment --> No effect is expected
37
Randomized control
Groups that receive different experimental treatments are determined randomly
38
False negative
A test result appears negative when it should have been positive
39
Disulfide group
R-S-S-R
40
Suloxide group
R-(S=O)-R'
41
Thioether vs. Thioester
```
Thioether = R-S-R
Thioester = R-(C=O)-S-R'
```
42
Thiol
S-H
43
Thioketone
R-(C=S)-R'
44
Solid-->Liquid-->Gas = _________
Gas>Liquid>Solid = ____________
Solid-->Liquid-->Gas = Endothermic - think free energy plot - Free energy is increasing = endothermic
Gas>Liquid>Solid = Exothermic
Gas has highest free energy
45
When a question says "how many additional isomers" what should you not do
Don't respond with "total" isomers. Addition = total-1
46
Half life problem: 93% degradation in 100 minutes, what is approximate half life
0.5^4 = 6.25% ~ 7%
| Therefore 4 half lives in 100 minutes, so half life = 25 minutes
47
Ka to pKa shortcut
4*10^5
| = (5-1).(10-4) = 4.6
48
Ksp of FeF2 Fe + 2F
Ksp = [Fe][F]^2
Plug in Q values (from experiment)
If Q>Ksp then the compound will precipitate
49
Low Low Ksp generally means ____
Not soluble
50
Unit of osmolarity
J/L
| Remember 1000L = 1 m^3
51
Osmotic Pressure equation
```
п = MRT
п = Osmotic pressure
M = Osmolarity of ALL IONS (sometimes can be given)
R = 8.314 J/mol/K
T = 273.15 K
```
52
To overcome static friction, the object (is/is not) moving become it overcomes that friction
It is NOT moving, it is NOT accelerating
53
Will 2 boxes of separate weights slide down the ramp with the same coefficient of friction?
ma = (mgsinƟ) - (μsmgcosƟ)
Masses cancel!
Therefore it doesn't matter the mass! They fall at equal times
54
Does elemental nitrogen undergo hydrolysis?
N2 is INERT dammit, nothing happens to that fucker
55
Hydrolysis of carbon dioxide forms___
```
Carbonic Acid (addition of OH to CO2)
Will lower pH of water
```
56
Silica is (polar/nonpolar)
Polar
| Therefore nonpolar molecules have highest Rf value since polar molecules will stick to silica plate
57
Can a nitrogen be part of an amide AND an amine
Yes. It can be both depending on the R groups
58
Proteins synthesized by ribosomes from ___ terminus to ____ terminus
N terminal to C terminal
Ends with a free carboxylic acid group (COOH)
Sometimes depending on invitro process this can flip
59
T/F: Benzene is inert
True, it will not react with reagents
60
Isoelectric focusing
Gel has a pH gradient maintained, and proteins (or AAs) will be in order of where their pI is on the gradient
61
Gas Chromatography
Walls of tube are a thin layer of polymer that is polar, so polar gases move slower.
62
Does Beta decay (+/-) change the atomic mass?
Very negligible change in atomic mass since electrons/positrons have very little mass
63
Electrons from which orbital are harder to eject, sp or sp3 and why
sp because they have more s character and electrons are closer to the nucleus
64
How come electron emission spectra shift to longer wavelengths than excitation?
Some energy is lost (vibrational) when electrons move from excited to ground state
65
R & S vs. L & D
R and S are ABSOLUTE
| L and D are RELATIVE
66
How to find pH of 0.1 M aspirin (pKa = 3.5)
```
10^(-3.5) = Ka = [H+][A-]/[HA]
x^2 / (0.1-x) = 10^-3.5
10-3.5(0.1) = x^2
10-4.5 = x^2
[10-2.25][10-2.25] = x^2
10^-2.25 = x
pH = 2.25
```
67
Addition of CO2 usually is a _______ reaction and it adds a _____ group
Carboxylation reactions which adds a carboxylic acid group
68
Galvanic cells consist of a maximum of ____ half reactions, so given more reduction potentials you should only use _____
2 half reactions
| Only use the two that are involved in the cell reaction
69
Contraction of ventricles does/doesn't involve influx of sodium
Depolarization, therefore sodium ions into cell during ventricle contraction
70
Name the following acids:
1) H3PO4
2) H2CO3
3) H2SO4
4) HIO3
5) HF
6) HNO2
1) phosphoric acid
2) carbonic acid
3) sulfuric acid
4) iodic acid
5) hydrofluoric acid
6) nitrous acid
- ous = -ic -1 oxygen
71
Why does a runner lean into the run?
To keep center of gravity in line with center of spine -- Forward lean matches ground reaction forces
72
Given the following elementary reaction, what is the rate law?
3A + B → 2C
Rate = k[A]3[B]
Since it is an ELEMENTARY reaction
73
What is STP
273K or 0 Celsius
| 1 atm pressure
74
Structure of Ribose
Furanose with another carbon on the side
75
Thin lens equation
1/o + 1/i = 1/f
| If it asks for a ratio, give a RATIO!
76
Electrolysis is exothermic or endothermic
Burning H2 is exothermic, so electrolysis and making it is ENDOTHERMIC
77
Work function and photon energy
KE of proton = hf - W
| W = work function
78
Adding base to carboxylic acid anhydride makes
Carboxylic acids
79
To separate amides from carboxylic acids and amines?
Neutralize with NaOH, then the amides are insoluble, so add diethyl ether then evaporate it to separate the amide
80
Kinetic vs. Thermodynamic control
```
Kinetic = lower activation E, so forms faster
Thermodynamic = higher actE, so slower formation but more stable since larger ∆G.
```
81
Transition metals lose which electrons first, s or d
Lose S electrons first, that's why a lot are +2 charged
| Configuration of Co(II) = [Ar] 3d^7 since 4s2 electrons lost
82
A kinase is what type of enzyme
Transferase
83
Color in spectrophotometer species is determined by:
Delocalization of electrons (look for conjugated double bonds)
84
What are the axes on Lineweaver Burk
-1/Km and 1/Vmax
85
What happens in Uncompetitive inhibition
Vmax reduced AND Km reduced
86
What is Histidine Charge at pH 5, 7, and 9
Histidine has pKa of 6, so it is +1 at pH 5, 0 at pH 7 and pH 9
If deprotonated it is neutral
87
Where is Vmax on lineweaver burk
The inverse of the y-intercept
88
How to number nitrogenous bases?
In order of priority:
1. Start at a nitrogen and go the direction that minimizes the number amount of nitrogens.
2. Minimize the number of Oxygens
3. Minimize the number on C-NH2s
89
Qualitatively describe the melting point of a protein
When 50% of molecule is unfolded and denatured (looks like equivalence point)
90
Glucose/Galactose/Fructose = Aldoses or Ketoses
Glucose and Galactose = Aldose
| Fructose = Ketose
91
Which has more H-bond acceptors Guanine or Cytosine
G donates to C
G has 2 NHs, 1 O
C has 1 N, 1 O, and 1 NH
Therefore Cytosine has more H-bond acceptors
92
Reducing Sugars
Lactose, Maltose
93
Non-reducing Sugar
Sucrose
94
For Purification yield
Match units of initial and final amounts of protein
95
Ternary complex
Ternary = 3 parts
96
T/F Unfolding of proteins is a cooperative process
True - The curve is sigmoidal
97
Snells law -- Law of refraction
n1v1=n2v2
| n1sinθ1=n2sinθ2
98
For AC Current, voltage is:
RMS voltage
| = Vmax * Sqrt(2)/2
