Flashcards
(264 cards)
1
Q
Can molecules with polar bonds be non polar?
A
Yes if there is no net dipole moment
2
Q
What is the shape of an s orbital?
A
spherical
3
Q
what is the shape of p orbital?
A
bi-lobed
4
Q
Which type of bonds form between atoms with small differences in electronegativity (.4-1.7)?
A
polar covalent bonds
5
Q
Which type of bond forms between atoms with the same electronegativities?
A
non polar covalent bonds
6
Q
What is a coordinate covalent bond?
A
one in which a pair of bonding electrons originates from just one of the atoms.
7
Q
(T/F) A dipole moment exist when a molecule has a separation of positive and negative charges.
A
true
8
Q
What is the formula for calculating formal charge on an atom involved in a covalent bond?
A
Formal charge= V-(1/2 N bonding + N nonbonding)
9
Q
What are resonance structures?
A
2 or more non-identical lewis structures for the same molecules
10
Q
(T/F) A lewis structure with small or no formal charges is preferred over one with large formula charges.
A
true
11
Q
Should a negative formal charge be placed in highly electronegative atoms or weakly electronegative atoms?
A
highly electronegative atoms.
12
Q
what are the bond orders of single, double, and triple bonds?
A
single=1st order
double=2nd order
triple=3rd order
13
Q
(T/F) A triple bond is longer than a single bond..
A
False
14
Q
What is a bond energy?
A
amount of energy required to separate two bonded atoms
15
Q
Can both bonding and nonbonding electrons be valence electrons?
A
yes.
nonbonding e- = not involved in a bond
bonding e- = involved in a bond
16
Q
Which type of elements contains the halogens?
A
group VIIA
17
Q
Which group of elements contains alkaline earths?
A
group IIA
18
Q
Which group of elements contains noble gases?
A
group VIIIA
19
Q
Which groups of elements contain the transition metals?
A
groups IB to VIIIB
20
Q
what is an ionic bond?
A
transfer of electrons between two atoms
21
Q
what is a covalent bond?
A
sharing of electrons between two atoms
22
Q
what is a polar covalent bond?
A
has properties of ionic and covalent bonds. electrons are shared but not equal.
23
Q
what is a cation?
A
positively-charged ion
24
Q
(T/F) Metals are found on the left side of the periodic table and are good conductors of electricity and heat.
A
True
25
(T/F) Non metals are found in the middle of the periodic table and are malleable, ductile and shiny.
False
26
(T/F) Metalloids are found between the metals and nonmetals and have varying properties.
True
27
Which group of elements contains the alkali metals?
Group IA
28
What is the electron affinity trend within the periodic table?
increases left to right across a period & up a group.
29
(T/F) Group VIIIA elements have high electron affinities.
False
30
What is electronegativity?
measure of attraction an atom has for the electrons in a chemical bond.
31
What is the electronegative trend within the periodic table?
increases left to right across a period and up a group.
32
What happens to the number of electrons when one moves from left to right across a row?
added as you move across a row.
33
Are electrons more tightly held or less highly held as one moves down a column?
tightly
34
What is the atomic radii trend within the periodic table?
decrease as you move from left to right across a period and up a group.
35
Does a period run horizontally or vertically?
Horizontally
36
Does a group run horizontally or vertically?
Vertically
37
(T/F) Groups have the same valence configuration and have similar chemical properties.
True
38
Which group A or B contains the representative elements?
A
39
(T/F) one amu is equal to 1/12 the mass of a carbon-12 atom.
True
40
how many particles are in a mole?
6.02 x 10 ^23
41
what is atomic weight?
reflects the number of grams per mole of the element. The atomic weight is usually derived from a weighted average of the naturally occurring isotopes of the element.
42
what is an isotope?
different form of the same element due to a different number of neutrons.
43
What are the 3 steps for determining geometric configuration?
1. draw lewis structure
2. count bonding and non bonding electron pairs in the valence shell of the central atom
3. arrange the electron pairs around the central atom so that they are as far apart as possible.
44
what is an anion?
negatively- charged ion.
45
which type of bonds forms between two atoms with substantial differences in electronegativities (>1.7)?
ionic bonds
46
(T/F) all atoms bond according to the "octet rule"
False.
47
what are some characteristics of ionic compounds?
crystal lattices
conduct electricity in solution
high melting
boiling points
48
what is ionization energy?
energy required to completely remove an electron from an atom.
49
compare the values of the first ionization and second ionization energy of an atom.
second ionization higher than first
50
what is electron affinity?
energy released when an atom accepts an electron.
51
How s a photon's energy related to its wavelength?
energy is inversely proportional to wavelength
52
How is a photon's energy related to its frequency?
energy is proportional to frequency
53
What is a paramagnetic material?
unpaired electrons
54
What is a diamagnetic material?
no unpaired electrons
55
How many fourth quantum numbers (ms) are possible for an electron?
What are they?
two.
| +1/2 and -1/2
56
What is Hund's rule?
electrons will fill to create the max number of half-filled orbitals.
57
what are the first four subshells?
s,p,d and f
58
what is the formula for the max number of electrons allowed in a subshell?
(4l+2)
59
what does the magnetic (3rd) quantum number (ml) represent?
represent an orbital within a subshell. The possible values range from -l to l
60
How many orbitals can each subshell accommodate?
7
61
What are three types of intermolecular forces?
dipole-dipole interactions
hydrogen bonding
dispersion forces
62
state the intermolecular forces in order of increasing strength.
dispersion forces
63
which molecules, polar or non polar, typically have higher boiling points?
polar molecules typically have higher boiling points.
64
Geometric arrangement:
| CO2
Linear
65
Geometric arrangement:
| BH3
trigonal planar
66
Geometric arrangement:
| NH3
pyramidal
67
Geometric arrangement:
| CH4
tetrahedral
68
Geometric arrangement:
| PCl5
trigonal bipyramidal
69
Geometric arrangement:
| SF6
octahedral
70
How many more protons are in a carbon-14 from than in a carbon-12 atom?
none.
71
what is an atomic emission spectrum?
electrons fall to their ground state
72
what is an atomic absorption spectrum?
electrons are excited to higher energy levels.
73
define Heisenberg uncertainty principle.
it is impossible to know both the momentum and position of an electron at the same time.
74
what are valence electrons?
electrons farthest from the nucleus, as well as many electrons available for bonding.
75
Define the Pauli exclusion principle?
no two electrons in an atom can have the same quantum numbers.
76
what does the principal (1st) quantum number (n) represent?
shell
77
what is the maximum number of electrons allowed in the second shell (n=2)?
2n^2
78
What does the azimuthal (2nd) quantum number (l) represent?
subshell
79
Classify the Rxn:
| A+X -> AX
Combination or additon
80
Classify the Rxn:
| AX -> A + X
decomposition
81
Classify the Rxn:
| AX + B -> BX + A
single displacement
82
Classify the Rxn:
| AX+ BY -> AY + BX
double displacement
83
Classify the Rxn:
| HA (aq) + BOH (aq) -> AB (aq) + H2O
neutralization
84
What is an empirical formula?
simplest whole number ratio of the element in a compound.
85
What is a molecular formula?
actual number of atoms each element present in a molecule of the compound.
86
what is the formula for calculating % composition
mass of X compound / MW of compound x 100%
87
What is molar mass (molar weight)?
Number of grams per molecule
88
what is the formula for gram equivalent weight?
Molar mass / n = Gram equivalent weight.
89
what is the formula for calculating equivalents?
Weight of compound/ Gram equivalent weight= equivalents
90
How do increasing temp and reactant concentration affect the rate of the reaction?
increases the rate of most reactions.
91
can the medium in which a reaction takes place affect the reaction rate?
yes
92
how does a catalyst increase reaction rate?
by decreasing activation energy
93
what is the reaction rate of the following one step reaction:
2A + B -> A2B
Rate = k [A]^2 [B]
94
what is the enthalpy change of a reaction?
difference between potential energy of the products and the potential energy of the reactants
95
what is the general formula for the rate law of the following reaction?
aA + bB -> cC + dD
rate= k [A]^x [B]^y
96
What is the reaction order for the following rate law?
| rate= k [A] [B]^2
Reaction order =3
| x=1, y=2, and order =x+y
97
Is the rate of a zero order reaction dependent on the concentration of the reactants?
No, a zero order reaction has a constant rate that is independent of the concentration of reactants.
98
what is an elementary reaction?
reaction that can not be decomposed into other reactions
99
(T/F) A complex reaction can be broken down into two or more elementary reactions.
True
100
what is an intermediate?
complex that appears during the course of a reaction but does not appear in the net reaction or as a final product.
101
what is the rate determining step of a reaction?
slowest step of a reaction
102
what is theoretical yield?
amount of product that can be predicted
103
what is actual yield?
amount of product actually isolated from the run experimentally
104
What is percent yield and what is the formula for calculating it?
relationship between actual yield and theoretical yield
| actual/theoretical x 100%
105
What is the equilibrium constant expression for the following reaction:
A+ 3B -> 2C + 2D
Keq= [C]^2 [D]^2 / [A] [B]^3
106
Do pure solids or liquids appear in an equilibrium constant expression?
No
107
Does Keq for a reaction remain constant at all temperatures?
No
108
If there is much more product than reactant at equilibrium, what can be said of Keq (as compared to 1)?
Keq>1
109
If Keq is very small compared to 1, then what can be said about the amount of reactants and products at equilibrium?
Keq
110
According to Le Chatelier's principle, in which direction will equilibrium shift if products are removed?
will shift to favor the forward reaction.
111
(T/F) Increasing the pressure of a system will shift equilibrium so as to increase the number of moles produced.
False.
| Increasing pressure will shift equation so as to produce fewer molecules of gas.
112
What is an isolated system?
an isolated system can not exchange energy or matter with its surroundings.
113
What is a closed system?
a closed system can exchange energy but can not exchange matter with its surroundings.
114
what is an open system?
an open system can exchange both energy and matter with its surroundings
115
what is an isothermal process?
process that can occur @ constant temp.
116
what is an isobaric process?
process that takes place @ constant pressure.
117
what is an adiabatic process?
process to which no heat exchange occurs between the system and the surroundings
118
(T/F) heat absorbed by a system is considered positive and heat lost by a system is considered negative.
true
119
what is an endothermic process?
process that absorbs heat from the surroundings.
120
what is an exothermic process?
release heat
121
what is the formula for calculating heat (q) absorbed or released by a process.
q= (mass)(heat capacity)(change in temp)= mcAt
122
what is the formula for calculating Delta Hrxn?
(sum of Delta Hf of products)-( Sum of Delta Hf of reactants)
123
Does a positive Delta H correspond to an endothermic or exothermic process
endothermic process.
124
Does a negative Delta H correspond to an endothermic or exothermic process?
exothermic
125
What is standard heat of formation ( Deta Hf)?
enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states.
126
What is the Delta Hf of an element in its standard state?
0
127
(T/F) Hess's law states that enthalpies of reactions are additive.
True
128
If the Delta H of a forward reaction is -220kJ, what is the Delta H of the reverse reaction?
+220kJ
129
What is bond dissociation energy?
amount of energy required to break a particular bond in one mole of gaseous molecules.
130
What is entropy?
measure of disorder or randomness of a system.
131
When does a system reach max entropy?
@ equilibrium
132
What is the Gibb's free energy equation? ΔG=
ΔG= ΔH- T ΔS
133
How does the value of ΔG correlate with the spontaneity of a reaction?
Δ G is negative for spontaneous rxn.
| Δ G is positive for non-spontaneous run
134
What is the value of ΔG for a system @ eq?
0
135
(T/F) A reaction with (+) ΔH and (-) ΔS is always spontaneous.
False
136
Under what conditions will a run with (+) ΔH and (+) ΔS be spontaneous?
@ high temp
137
under what conditions will a reaction with (-)ΔH and (-) ΔS be spontaneous?
@ low temp
138
what is standard free energy, ΔG?
process occurring @ 25 C, 1 atm of pressure and when the concentrations of all reactant and products are 1M
139
what is standard free energy formation ΔGf?
free energy change that occurs when 1 mol of a compound in its standard state is formed from its elements in their standard states.
140
what is the formula relating ΔG to Keq?
ΔG= -RT ln Keq
141
(T/F) Once a reaction commences:
| ΔG= ΔG+ RTln Q
True
142
What are the three phases of matter?
solid
liquid
gas
143
What is standard pressure in atm, mm Hg and torr?
1atm=760 mmHg= 760 torr
144
What is standard term in Kelvin? celsius?
273 K
| 0C
145
(T/F) an ideal gas represents a hypothetical gas whose articles take up no volume and experience no intermolecular forces.
True
146
What is Boyle's law?
under isothermal conditions, pressure is inversely proportional to volume.
P1V1=P2V2
147
What is Charles Law?
under constant pressure, volume is directly proportional to absolute temp.
(V1/T1)=(V2/T2)
148
(T/F) Avogadro's principle states that at constant temp and pressure, volume is directly proportional to the number of moles of gas.
True
149
what is the ideal gas law?
PV=nRT
150
what is the difference between I.P and Ksp?
I.P is defined with respect to initial concentrations.
| Ksp is defined with respect to the concentrations of a saturated solution at equilibrium.
151
(T/F) Metals, which are on the left side of the periodic table, generally form positively-charged ions. non-metals on the right side generally from negative-charged ions.
True
152
What is an electrolyte?
solute whose solution is conductive
153
What is the formula for percent composition by mass?
mass of solute/ mass of solution x 100%
154
What is the definition of mole fraction (X)?
moles of compound/ total number of moles.
155
What is the definition of molarity?
moles of solute/ L in solution
156
what is the definition of molality?
moles of solute/ Kg of solvent
157
what is the definition of normality?
GEW of solute/ L of solute.
158
(T/F) A solution which is diluted is related to its initial concentration as follows: M1V1= M2V2
True
159
Name:
| Cu+
Copper (I)
or
Cuprous
160
Name:
| Cu+2
Copper (II)
or
Cupric
161
Name:
| H-
Hydride
162
Name:
| ClO-
Hypochlorite
163
Name:
| ClO2-
Chlorite
164
Name:
| ClO3-
Chlorate
165
Name:
| ClO4-
Perchlorate
166
What is the Arrhenius definition of an acid?
| Of base?
Arrhenius acid: produces H+ in aq solution.
| Arrhenius base: produces OH- in aq solution.
167
What is the Bronsted-Lowry definition of an acid?
donates protons
168
What is the Bronsted-Lowry definition of an base?
accepts protons
169
If the I.P is larger than the solubility product constant (Ksp), is the solution saturated. unsaturated or supersaturated?
I.P> Ksp supersaturated
170
If the I.P is smaller than the solubility product constant (Ksp), is the solution saturated. unsaturated or supersaturated?
I.P
171
If the I.P is equal than the solubility product constant (Ksp), is the solution saturated. unsaturated or supersaturated?
I.p = Ksp saturated
172
what is the common ion effect?
when a slightly soluble salt is added to a solution which already contains one of its components, the added salt is less soluble than if it were added to a pure solvent.
173
what is the name of the process for combing smaller nuclei into larger nuclei?
Fusion is the combining of smaller nuclei to create a larger nuclei.
174
what is nuclear fission?
splitting of atomic nuclei
175
Define reduction potential
tendency of species to acquire electrons.
176
Whats the formula for EMF
EMF= E red+ E ox
177
(T/F) When adding standard potentials, multiply by the number of moles oxidized or reduced first.
False
178
what is the formula for the standard free energy of an electrochemical cell?
ΔG= -(number of moles) (Faraday's constant)(EMF)
| = -nFE
179
what is the relationship between EMF and Keq?
nFE= RT ln Keq
180
If the half life of an isotope is 2 years, how much of the original isotope will be left after 4 years?
25%
181
What is the formula for exponential decay?
n=no e ^ -λt
182
what is mass defect?
difference between the mass of a nucleus and the sum total of its constituents (nucleons)
183
what formula is used for calculating binding energy?
Energy= (mass defect)(speed of light)^2
| Δmc^2
184
What is the oxidation number of free elements?
0
185
(T/F) Group IA elements usually have a +1 charge in a compound, and group IIA usually have a +2
true
186
what is the oxidation number of oxygen in most compounds?
-2
187
What is the oxidation number of Group VIIA element in a compound?
- 1
except: if a group VIIA element is combined with and element with higher electronegativity, then the oxidation number is +1 or higher
188
what are the two types of electrochemical cells?
galvanic (voltanic)
| electrolytic
189
does oxidation occur at the anode or cathode?
anode
190
does reduction occur at the anode or cathode?
cathode
191
which type of electrochemical cell generates energy?
galvanic
192
Does a galvanic cell have a positive or negative ΔG?
negative= spontaneous
193
what is the function of a salt bridge?
permits balancing of charge between cells
194
(T/F) A cell diagram adheres to the following conventions:
| anode/anode solution// cathode solution/cathode
true
195
does an electrolytic cell have positive or negative ΔG?
positive= non- spontaneous
196
In which electrochemical cell is the anode positive?
electrolytic cell
197
In which electrochemical cell is the cathode positive?
galvanic cell
198
what is faraday (F)?
F is equivalent to the amount of charge contained in one mole of electrons = 96,487 C.
199
(T/F) Electrons always flow from the anode to the cathode.
True
200
(T/F) An acid equivalent is equal to one mole of H+
True
201
Does high Ka correspond to weak or strong acid?
High Ka= strong acid
202
Does high Kb correspond to weak or strong acid?
High Kb= weak acid.
203
What is a polyprotic acid?
can lose more than one proton
| ie: H2SO4 or H3PO4
204
what is an amphoteric species?
can act as acid or base
205
ph?
| Strong acid + Strong base
pH of 7
206
pH?
| Weak acid + Strong base
pH greater than 7
207
(T/F) A buffer solution consist of a mixture of a strong acid and its salt
False.
| buffer= mix of weak acid & its salt
208
What is the henderson-Hasselbalch equation for a weak acid buffer solution?
pH= pKa + Log (conjugate base)/(weak acid)
209
What is the Henderson-Hasselbalch equation for a weak base buffer solution?
pOH=pKb + log (conjugate acid)/(weak base)
210
Does the gain of electrons result in reduction or oxidation?
reduction
211
Does the loss of electrons result in reduction or oxidation?
oxidation
212
(T/F) An oxidizing agent is oxidized in an electrochemical reaction.
False
213
what is a reducing agent?
species that loses electrons and thereby causes another agent to be reduced.
214
What is the lewis definition of an acid?
accepts electron pair
215
What is the lewis definition of an base?
donates electron pair
216
(T/F) All broasted-lowry acids are lewis acids.
true
217
Name:
| HF
Hydrofluoric acid
218
Name:
| HClO4
Perchloric acid
219
Name:
| HNO2
Nitrous acid
220
Name:
| HNO3
Nitric acid
221
what is the water dissociation constant @ 25 C? Kw=
Kw=[H+][OH-]=10^-14
222
What is the pH of a solution @ 25C with a pOH of 5?
pH= 14-pOH =9
223
What is the log formula for calculating pH?
pH= -log [H+]
224
What is the log formula for calculating pOH?
pOH= -log [OH-]
225
What is the pH of a 1 x 10^-14 M HCl solution?
pH=4
226
would the pH of a 1.4 x 10^-14 M HCl solution be greater or less than 4?
less than 4
227
What is the product of a neutralization reaction?
salt
228
will the titration of a weak acid with a strong base produce a slightly acidic or slightly basic solution?
basic
229
will the titration of a strong acid with a strong base produce a slightly acidic or slightly basic or neutral solution?
neutral
230
will the titration of a strong acid with a weak base produce a slightly acidic or slightly basic solution?
acidic
231
(T/F) Solids and liquids are often referred to as the condensed phases.
True
232
What does it mean when two liquids are immiscible?
liquids repel each other and do not mix to form a solution.
233
What is an emulsion?
mix of immiscible liquids which are broken up into extremely small particles.
234
What is an amorphous solid?
no ordered 3D arrangement.
235
What are the two most common types of crystalline solids?
ionic & metallic
236
(T/F) A unit cell is a repeating unit of crystals
True
237
What is condensation?
| Evaporation?
Condensation: gas to liquid
Evaporation: liquid to gas
238
What is fusion?
solid to liquid
239
what is solidification (crystallization)?
liquid to solid
240
What is sublimation?
solid to gas
241
what is deposition?
gas to solid
242
(T/F) The rates at which two gases diffuse are inversely proportional to the square root of their molar masses.
true
243
what is effusion?
flow of gas particles under pressure from one container to another through a small opening.
244
(T/F) The rates of effusion for 2 molecules are directly proportional to the square root of their molar masses.
False.
245
What is Dalton Law of Partial pressure?
the total pressure of a gaseous mix is equal to the sum pf partial pressure of the individual components.
246
What is the formula for calculating partial pressure?
PA= Pt XA ; XA= mol of A/ total mol
247
(T/F) A gas molecule's kinetic energy is inversely proportional to the absolute temp of the gas
False.
| Kinetic energy is directly proportional to the absolute temp.
248
Under what conditions is the ideal gas law most correct?
gases behave in a near-ideal fashion at low temp and high temp.
249
How do actual volume and predicted volume of a gas compare at moderately high pressures? Extremely high pressures?
Moderately high: gas volume less than would be predicted
| Extremely high: gas volume more than would be predicted
250
How do actual volume and ideal volume of a gas compare at very low temp?
low temp: actual volume less than would be predicted.
251
What is the volume of 1 mole of gas at STP?
22.4 L
252
What are the typical units of density for a gas?
g/L
253
(T/F) For a specific sample of gas, (P1VA/T1)=(P2V2/T2)
True
254
What is the formula for calculating the density of a gas?
d=m/V= P(MM)/RT
255
What is an aqueous solution?
one which water is the solvent
256
what is solubility?
measure of the amount of substance that can be dissolved in a particular solvent @ a particular temp
257
what is a saturated solution?
contains mx amount of solute that can be dissolved in a particular solvent @ a particular temp
258
Is osmotic pressure proportional to molarity?
yes
259
What is the formula for osmotic pressure?
π= MRT
260
What is the formula for the vapor pressure of A in a solution of A and B?
PA= XA PA
261
What is a colligative property?
property derived sole from the number of particles present, not the nature of those particles.
262
Name the 4 colligative properties.
freezing point depression
boiling point elevation
osmotic pressure
vapor pressure lowering
263
What is the formula for freezing-point depression?
ΔTf=Kf m
264
What is the formula for boiling-point elevation?
ΔTb= Kb m
