College Chemistry II Practice Exam 1
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which of the following statements is not true?
A) The reverse of a spontaneous reaction is always nonspontaneous.
B) A spontaneous process always moves toward equilibrium.
C) A nonspontaneous process cannot be caused to occur.
D) A highly spontaneous process need not occur rapidly.
1) _______
2) _______
2) Which forward reaction is a nonspontaneous process?
A) the expansion of a gas into a vacuum
B) N2(g) + 3 H2(g) ⇌ 2 NH3(g)
if PH₂ = PN₂ = 1 atm, PNH₃ = 0, and Kp = 4 × 105
C) 2 NH3(g) ⇌ N2(g) + 3 H2(g)
if PNH₃ = 1 atm, PH₂ = PN₂ = 0, and Kp = 2 × 10-6
D) none of the above
3) The chemical system shown below is at equilibrium. Which change in conditions will not
result in a spontaneous forward reaction?
N2(g) + 3 H2(g) ⇌ 2 NH3(g)
Kp = 4 × 105
A) adding a catalyst
B) adding more H2
C) adding more N2
D) reducing the volume
4) Classify each of the following processes as spontaneous or nonspontaneous.
I. H2O(l) → H2O(g) T = 25°C, vessel open to atmosphere with 50% relative humidity
A)
B)
C)
D)
3) _______
4) _______
II. H2O(s) → H2O(l) T = 25°C, P = 1 atm
I and II are both spontaneous.
I is spontaneous and II is nonspontaneous.
I is nonspontaneous and II is spontaneous.
I and II are both nonspontaneous.
5) The reaction A(g) → B(g) is spontaneous under standard conditions. Which of the following
statements must be true?
I. The reaction B(g) → A(g) is nonspontaneous under standard conditions.
II. A(g) will be completely converted to B(g) if sufficient time is allowed.
III. A(g) will be completely converted to B(g) rapidly.
A) none of these
B) I
C) I and II
D) I, II, and III
5) _______
6) Which of the following processes are spontaneous?
I. dissolving more solute in an unsaturated solution
II. dissolving more solute in a saturated solution
III. dissolving more solute in a supersaturated solution
A) none of these
B) I
C) I and II
6) _______
7) Which of the following processes is spontaneous?
A) a mixture of two gases separating into pure compounds
B) reaction of sodium with oxygen
C) precipitation of solute from a saturated solution
D) water flowing uphill
D) I, II, and III
7) _______
8) Entropy is a measure of
A) free energy.
C) molecular randomness.
8) _______
B) the heat of a reaction.
D) the rate of a reaction.
9) For which of the following will the entropy of the system increase?
A) condensation of steam
B) reaction of magnesium with oxygen to form magnesium oxide
C) reaction of nitrogen and hydrogen to form ammonia
D) sublimation of dry ice
10) For which process is the sign of △S negative in the system?
A) 2 H2(g) + O2(g) → 2 H2O(g)
9) _______
10) ______
B) 2 H2O(l) + 2 K(s) → 2 K+(aq) +2 OH–(aq) + H2(g)
C) H2O(s) → H2O(g)
D) H2O(l) → H2O(g)
11) Predict the sign of ΔS of the system for both of the following.
I. 2 C(graphite) + O2(g) → 2 CO(g)
11) ______
II. C4H10(g) → C4H10(l)
A)
B)
C)
D)
ΔS should be negative for I and negative for II.
ΔS should be negative for I and positive for II.
ΔS should be positive for I and negative for II.
ΔS should be positive for I and positive for II.
12) Sodium reacts violently with water according to the equation:
2 Na(s) + 2 H2O(l) → 2 NaOH(aq) + H2(g)
12) ______
The resulting solution has a higher temperature than the water prior to the addition of sodium.
What are the signs of
and
for this reaction?
A) ΔH° is negative and ΔS° is negative.
B) ΔH° is negative and ΔS° is positive.
C) ΔH° is positive and ΔS° is negative.
D) ΔH° is positive and ΔS° is positive.
13) The brown color associated with photochemical smog is due to NO2(g), which is involved in an
13) ______
equilibrium with N2O4(g) in the atmosphere.
2 NO2(g) ⇌ N2O4(g)
Predict the signs of the enthalpy and entropy change for the forward reaction.
A) The enthalpy change is negative and the entropy change is negative.
B) The enthalpy change is negative and the entropy change is positive.
C) The enthalpy change is positive and the entropy change is negative.
D) The enthalpy change is positive and the entropy change is positive.
14) What is W in Boltzmann's formula, S = k ln W?
A) a fraction indicating the probability of obtaining a result
B) a random number
C) the number of ways of obtaining the state
D) the work times Avogadro's number
14) ______
15) Which electron on an atom of copper would have the highest value of W in the Boltzmann
formula?
A) 3s
B) 3d
C) 4s
D) 4p
15) ______
16) An electron in an oxygen p orbital on which of the following would have the highest entropy?
16) ______
A) CH3CH2OH
B) CH3CH2O–
C) CH3CO2OH
D) CH3CO2–
17) What is k in Boltzmann's formula, S = k ln W?
A) the degeneracy of the state
B) the equilibrium constant for the process
C) the universal gas constant divided by Avogadro's number
D) the universal gas constant times Avogadro's number
17) ______
18) The entropy change associated with the expansion of one mole of an ideal gas from an initial
volume of Vi to a final volume of Vf at constant temperature is given by the equation, ΔS = R ln
18) ______
(Vf/Vi). What is the entropy change associated with the expansion of three moles of an ideal gas
from an initial volume of Vi to a final volume of Vf at constant temperature?
A) ΔS = R ln (Vf/Vi)
B) ΔS = 3 mol × R ln (Vf/Vi)
C) ΔS = R ln (Vf × 23/Vi)
D) ΔS = R ln (Vf × 3!/Vi)
19) What is the entropy change associated with the expansion of one mole of an ideal gas from an
initial volume of V to a final volume of V of 2.50V at constant temperature?
A) ΔS = 2.50 R ln (Vf/Vi)
B) ΔS = -2.50 R ln (Vf/Vi)
C) ΔS = R ln 2.50
19) ______
D) ΔS = -R ln 2.50
20) Predict the sign of ΔS for each of the following processes, which occur at constant temperature.
I. The volume of 2.0 moles of O2(g) increases from 44 L to 52 L.
20) ______
II. The pressure of 2.0 moles of O2(g) increases from 1.0 atm to 1.2 atm.
A) I: ΔS= negative; II: ΔS= negative
C) I: ΔS= positive; II: ΔS= negative
B) I: ΔS= negative; II: ΔS= positive
D) I: ΔS= positive; II: ΔS= positive
21) Assume a heteronuclear diatomic molecule, AB, forms a one-dimensional crystal by lining up
along the x-axis. Also assume that each molecule can only have one of six possible orientations,
corresponding to atom A facing in either the positive or negative direction along the x-, y-, or
z-axis. If the molecules are arranged randomly in the six directions, the molar entropy at
absolute zero should be
A) R ln 6.
B) R ln 66.
C) R ln 6!
D) 0.
21) ______
22) The Boltzmann formula is S = k ln W. A perfect crystal has a molar entropy of 0 at absolute zero
because
A) W = 0.
B) W = 1.
C) W = NA.
D) k = 1.
22) ______
23) What is the sign of △S for each of the following processes?
23) ______
I.
The separation of gaseous molecules of UF6, into 238UF6 and 235UF6 at constant
temperature and pressure.
II. The dissolving of I2(s) in CCl4(l).
A) ΔS is negative for I and negative for II.
C) ΔS is positive for I and negative for II.
24) Which has the lowest entropy?
A) CH3OH(s, –25°C)
C) CH3OH(l, 15°C)
B) ΔS is negative for I and positive for II.
D) ΔS is positive for I and positive for II.
24) ______
B) CH3OH(s, –15°C)
D) CH3OH(l, 25°C)
25) Which has the highest entropy in each set?
I. H2O(s), H2O(l), H2O(g) at 0.1°C, 4.58 atm
I
I
.
H
2
O
(
l
)
a
t
0
°
C
,
H
2
O
(
l
)
a
t
2
5
°
C
,
H
2
O
(
l
)
a
t
1
0
0
°
C
(
a
ll
a
t
1
.
0
a
t
m
p
ressure)
25) ______
A) H2O(l) in set I and H2O(l) at 0°C in set II
B) H2O(s) in set I and H2O(l) at 100°C in set II
C) H2O(g) in set I and H2O(l) at 0°C in set II
D) H2O(g) in set I and H2O(l) at 100°C in set II
26) Which provides the greatest increase in entropy?
A) H2O (s, 0°C) → H2O (l, 0°C)
C) H2O (g, 0.1°C) → H2O (s, 0.1°C)
26) ______
B) H2O (l, 0°C) → H2O (l, 25°C)
D) H2O (l, 100°C) → H2O (g, 100°C)
27) According to the third law of thermodynamics,
A) energy is conserved in any transformation of matter.
B) the entropy increases for any spontaneous process.
C) the entropy of a perfectly ordered, crystalline substance is zero at 0 Kelvin.
D) the entropy of the universe increases for any spontaneous process.
27) ______
28) Which of the following statements must be true for the entropy of a pure solid to be zero?
I. The temperature must be 0 K.
II. The solid must be crystalline, not amorphous.
III. The solid must be perfectly ordered.
IV. The solid must be an element.
A) I
B) I and II
C) I, II, and III
D) I, II, III, and IV
28) ______
29) Under which of the following conditions would one mole of Ne have the highest entropy, S?
A) 27°C and 25 L
B) 137°C and 25 L
C) 27°C and 35 L
D) 137°C and 35 L
29) ______
30) Which has the highest standard molar entropy at 25°C?
A) Al(s)
B) Al(l)
C) Al(g)
D) All three should have a standard molar entropy of zero.
30) ______
31) Which has the highest standard molar entropy at 25°C?
A) F2(g)
B) Cl2(g)
C) Br2(g)
31) ______
D) I2(g)
32) Which of the following gas molecules has the greatest standard molar entropy at 25°C?
A) C2H2
B) CH2CH2
C) CH3CH3
D) All have the same entropy.
33) Which substance has the highest standard molar entropy at 25°C ?
A) C(graphite)
B) C2H4(g)
C) CH3OH(l)
33) ______
D) MgCO3(s)
34) Which one of the following has the lowest standard molar entropy, S°, at 25°C?"
A) C8H18(s)
B) C8H18(l)
C) C12H26(s)
D) C12H26(l)
35) Calculate ΔS° for the following reaction.
N2(g) + 2 O2(g) → 2 NO2(g)
32) ______
34) ______
35)
______
A) -156.5 J/K
B) -121.5 J/K
C) 15.5 J/K
D) 636.5 J/K
36) ______
36) ΔS° = – 198.7 J/K for the reaction shown below. Calculate S° for NH3(g).
N2(g) + 3 H2(g) → 2 NH3(g)
A) 61.7 J/K∙mol
B) 123.4 J/K∙mol
C) 192.3 J/K∙mol
D) 384.6 J/K∙mol
37) Calculate ΔS° for the formation of one mole of solid sodium bromide from the elements at 25°C.
A) -116.7 J/K
B) -81.2 J/K
C) -40.5 J/K
37) ______
D) 86.8 J/K
38) The standard molar entropy for Br2(g) is 245.46 J/(mol ∙ K) at 25°C. Given that ΔS° = 104.58 J/K
38) ______
for the dissociation of one mole of Br2(g) into Br(g) at 25°C, find the standard molar entropy for
Br(g) at 25°C.
A) 70.44 J/(mol ∙ K)
C) 175.02 J/(mol ∙ K)
B) 140.08 J/(mol ∙ K)
D) 350.04 J/(mol ∙ K)
39) Which of the three laws of thermodynamics provides a criterion for spontaneity?
A) the first law of thermodynamics
B) the second law of thermodynamics
C) the third law of thermodynamics
D) both the second and third laws of thermodynamics
39) ______
40) Which of the following is a criterion for spontaneity that holds for any process?
A) ΔG < 0
B) ΔG > 0
C) ΔStotal < 0
D) ΔStotal > 0
40) ______
41) According to the second law of thermodynamics, all reactions proceed spontaneously in the
direction that increases the entropy of the
A) surroundings.
B) system.
C) system – surroundings
D) system + surroundings
41) ______
42) For a process to be at equilibrium, it is necessary that
A) ΔSsys = ΔSsurr.
B) ΔSsys = - ΔSsurr.
C) ΔSsys = 0.
D) ΔSsys = 0 and ΔSsurr = 0.
42) ______
43) For a spontaneous process
A) energy and entropy are conserved.
B) energy is conserved and the entropy of the system and surroundings increases.
C) the energy of the system and the surroundings decreases and the entropy of the system and
surroundings increases.
43) ______
D) both the energy and the entropy of the system and surroundings decrease.
44) For the process
CaCO3(calcite) → CaCO3(aragonite)
44) ______
ΔH° = -0.21 kJ, ΔS° = -4.2 J/K
Assuming that the surroundings can be considered a large heat reservoir at 25°C, calculate
ΔSsurr and ΔStotal for the process at 25°C and 1 atm pressure. Is the process spontaneous at 25°C
and 1 atm pressure?
A) ΔSsurr = 4.2 J/K, Δtotal = 0, not spontaneous
B) ΔSsurr = 0.7 J/K, ΔStotal = -3.5 J/K, not spontaneous
C) ΔSsurr = -0.7 J/K, ΔStotal = -4.9 J/K, spontaneous
D) ΔSsurr = -0.7 J/K, ΔStotal = -4.9 J/K, not spontaneous
45) During perspiration,
A) the entropy of the water evaporated decreases and the entropy of the body decreases.
B) the entropy of the water evaporated decreases and the entropy of the body increases.
C) the entropy of the water evaporated increases and the entropy of the body decreases.
D) the entropy of the water evaporated increases and the entropy of the body increases.
45) ______
46) A hot penny is dropped into cold water inside a polystyrene foam cup. Assuming negligible heat
loss to the atmosphere and the cup,
A) the decrease in entropy of the penny is equal to the increase in entropy of the water.
∣ ΔSpenny ∣ = ∣ ΔSwater ∣
46) ______
B) the decrease in entropy of the penny is less than the increase in entropy of the water.
∣ ΔSpenny ∣ < ∣ ΔSwater ∣
C) the decrease in entropy of the penny is more than the increase in entropy of the water.
∣ ΔSpenny ∣ > ∣ ΔSwater ∣
D) the entropy of both the penny and the water increases.
47) At constant pressure and temperature, which statement is true?
A) All reactions for which △H < 0 are spontaneous.
B) All reactions for which △S < 0 are spontaneous.
C) All reactions for which △G < 0 are spontaneous.
D) All reactions for which K < 1 are spontaneous.
47) ______
48) Why is the sign of ΔG rather than the sign of ΔStotal generally used to determine the spontaneity
of a chemical reaction?
A) ΔG can be used for processes that occur under any conditions.
B) ΔG involves thermodynamic functions of the system only.
C) Free energy is easier to understand than entropy.
D) Entropy is based on probability and is therefore less reliable.
48) ______
49) Other than only PV work, what reaction conditions must be satisfied for the sign of ΔG to be
used as a criterion for spontaneity?
A) constant volume and pressure
B) constant temperature and pressure
C) constant temperature and volume
D) constant volume only
49) ______
50) For the reaction 3 C2H2(g) → C6H6(l) at 25°C, the standard enthalpy change is -631 kJ and the
50) ______
standard entropy change is -430 J/K. Calculate the standard free energy change at 25°C.
A) 948 kJ
B) -503 kJ
C) -618 kJ
D) -1061 kJ
51) For a particular process ΔG is less than ΔH. Therefore
51) ______
A)
B)
C)
D)
ΔS is positive.
ΔS is negative.
ΔS is zero.
ΔS is negative if ΔH is positive and ΔS is positive if ΔH is negative.
52) For a particular process, ΔG = ΔH at a given temperature and pressure. Therefore,
A) ΔS is positive if ΔH is positive and negative is ΔH is negative.
B) ΔS is negative if ΔH is positive and positive if ΔH is negative.
C) ΔS is zero.
D) ΔS = ΔG/T.
52) ______
53) The solubility of manganese(II) fluoride in water is 6.6 g/mL at 40°C and 4.8 g/L at 100°C. Based
on these data, what is the sign of ΔH° and ΔS° for the process below?
MnF2(s) ⇌ Mn2+(aq) + 2 F-(aq)
53) ______
A)
B)
C)
D)
ΔH° is negative but the sign of ΔS° cannot be determined from this information.
ΔH° is negative and ΔS° is definitely negative.
ΔH° is positive but the sign of ΔS° cannot be determined from this information.
ΔH° is positive and ΔS° is definitely negative.
54) At 25°C, ΔH° = 1.895 kJ and ΔS° = -3.363 J/K for the transition
C(graphite) → C(diamond)
Based on these data
A) graphite cannot be converted to diamond at 1 atm pressure.
B) diamond is more stable than graphite at all temperatures at 1 atm.
C) diamond is more stable than graphite below 290°C and graphite is more stable than
diamond above 290°C.
D) graphite is more stable than diamond below 290°C and diamond is more stable than
graphite above 290°C.
54) ______
55) For bromine, ΔH°vap = 30.91 kJ/mol and ΔS°vap = 93.23 JK-1mol-1 at 25°C. What is the normal
boiling point for bromine?
A) 25°C
B) 58°C
C) 124°C
D) 332°C
55) ______
56) Consider the reaction:
N2(g) + 3 F2(g) → 2 NF3(g)
56) ______
ΔH° = -249 kJ and ΔS° = -278 J/K at 25°C
Calculate ΔG° and state whether the equilibrium composition should favor reactants or products
at standard conditions.
A) ΔG° = -332 kJ; the equilibrium composition should favor products.
B) ΔG° = -332 kJ; the equilibrium composition should favor reactants.
C) ΔG° = -166 kJ; the equilibrium composition should favor products.
D) ΔG° = -166 kJ; the equilibrium composition should favor reactants.
57) Which statement is true about the formation of CaCO3(s) from CaO(s) and CO2(g) at 1.00 atm?
CaO(s) + CO2(g) → CaCO3(s)
A)
B)
C)
D)
ΔH° = -178.7 kJ and ΔS° = -150.4 J/K
The reaction is spontaneous at all temperatures.
The reaction is spontaneous at high temperatures.
The reaction is spontaneous at low temperatures.
The reaction is not spontaneous at any temperature.
58) The signs of ΔG, ΔH, and ΔS at 25°C are shown below for three reactions.
57) ______
___
___
58)
Which
reaction
could go
in the
reverse
direction
at high
temperat
ure?
A) I
B) II
C) III
D) I and II
59) For the evaporation of water during perspiration on a hot, dry day,
A) ΔH is positive and TΔS = ΔH.
B) ΔH is positive and TΔS > ΔH.
C) ΔH is positive and TΔS < ΔH.
D) ΔH is negative and TΔS is positive.
59) ______
60) For the reaction below △G° = + 33.0 kJ, △H° = + 92.2 kJ, and △S° = + 198.7 J/K. Estimate the
temperature at which this reaction becomes spontaneous.
2 NH3(g) → N2(g) + 3 H2(g)
60) ______
A) 0.464 K
B) 166 K
C) 298 K
D) 464 K
61) ______
61) Calculate the standard free energy change at 25°C for the reaction
2 NO(g) + O2(g) → 2 NO2(g).
A) -4.7 kJ
B) -72.6 kJ
C) -157.8 kJ
D) -532.6 kJ
62) For any thermodynamic function Y, ΔY° for a reaction refers to the change in Y for the process in
which
A) the mixed reactants at 1 atm go to equilibrium at 1 atm.
B) the separate reactants at 1 atm go to equilibrium at 1 atm.
C) the separate reactants in their standard states are completely converted to separate
products in their standard states.
D) the spontaneous reaction occurs.
62) ______
63) Which of the following is true?
A) As a reaction at constant temperature and pressure goes to equilibrium, |ΔG| decreases.
B) The larger ΔG°, the faster the reaction.
C) The standard state for solutes is the pure solute at 1 atm.
D) When a reaction reaches equilibrium, ΔG° = 0.
63) ______
64) Which statement is true concerning the standard states of F2(g) and C6H12O6(aq)?
64) ______
A) The standard state for F2(g) is the pure gas at 1 atm and for C6H12O6(aq) is the pure solid
at 1 atm.
B) The standard state for F2(g) is the pure gas at 1 mol/L and for C6H12O6(aq) is the pure
solid at 1 atm.
C) The standard state for F2(g) is the pure gas at 1 atm and for C6H12O6(aq) is the solution at
a concentration of 1 mol/L.
D) The standard state for F2(g) is the pure gas at 1 mol/L and for C6H12O6(aq) is the solution
at a concentration of 1 mol/L.
65) ______
65) Calculate the standard free energy for the reaction given.
2 CH3OH(l) + 3 O2(g) → 2 CO2(g) + 4 H2O(l)
A) -465.2 kJ
B) -797.8 kJ
C) -1404.8 kJ
D) -2069.8 kJ
66) ______
66) Which is the lowest at 25°C?
A) ΔG°f for H2O (s)
B) ΔG°f for H2O (l)
D) 1/2ΔG°f for O2 (g) plus ΔG°f for H2O (g)
C) ΔG°f for H2O (g)
67) ______
67) Which of the following is zero at 25°C?
A) ΔG°f for N2(g)
B) ΔG°f for H2O (l)
D) S° for H2O (l)
C) S° for N2 (g)
68) A positive value of ΔG°f for a solid compound at 25°C means the
A)
B)
C)
D)
compound cannot exist at 25°C and 1 atm.
compound must be a liquid or a gas at 25°C and 1 atm.
process of forming the compound from the elements is exothermic.
process of forming the compound from the stable elements at 25°C and 1 atm is
nonspontaneous.
69) At 25°C, ΔG°f is -620 kJ/mol for SiCl4(g) and -592 kJ/mol for MgCl2(s). Calculate ΔG° for the
reaction,
25°C if the pressure of SiCl4(g) is 1 atm.
A)
B)
C)
D)
68) ______
69) ______
and determine if the reaction is spontaneous at
ΔG° = 28 kJ; the process is spontaneous.
ΔG° = 28 kJ; the process is nonspontaneous.
ΔG° = -564 kJ; the process is spontaneous.
ΔG° = -564 kJ; the process is nonspontaneous.
70) Which of the following are unstable with respect to their constituent elements at 25°C?
A) C8H18(l), CH3OH(l)
B) C8H18(l), C2H2(g)
70) ______
C) C2H2(g)
D) CH3OH(l)
71) In general, as a reaction goes to equilibrium
A) ΔG decreases.
C) ΔG goes to zero.
71) ______
B) ΔG°f decreases.
D) ΔG° decreases.
72) ______
72) At 25°C, ΔG° = -198 kJ for the reaction, NO(g) + O3(g) ⇌ NO2(g) + O2(g).
Calculate ΔG under the following conditions:
A) -159 kJ
B) -167 kJ
C) -198 kJ
D) -236 kJ
73) For a reaction at constant temperature, as Q increases
A) ΔG and ΔG° increase.
B) ΔG and ΔG° decrease.
C) ΔG increases, but ΔG° remains constant.
D) ΔG decreases, but ΔG° remains constant.
73) ______
74) At high temperatures boron carbide vaporizes according to the equation
B4C(s) ⇌ 4 B(g) + C(s)
74) ______
Which equation describes the relationship between ΔG° and ΔG for this reaction?
A) ΔG = ΔG° + R T ln (pB ∙ [C]/[B4C])
B) ΔG = ΔG° + R T ln pB
C) ΔG = ΔG° + 4 R T ln pB
D) ΔG = ΔG° - 4 R T ln pB
75) At 2600 K, ΔG° = 775 kJ for the vaporization of boron carbide:
B4C(s) ⇌ 4 B(g) + C(s)
75) ______
Find ΔG and determine if the process is spontaneous if the reaction vessel contains 4.00 mol
B4C(s), 0.400 mol of C(s), and B(g) at a partial pressure of 1.0 × 10-5 atm. At this temperature, R T
= 21.6 kJ.
A) ΔG = -270 kJ; spontaneous.
C) ΔG = -220 kJ; spontaneous.
76) ΔG = ΔG° for a reaction
A) if Q = K.
C) at STP.
B) ΔG = -270 kJ; nonspontaneous.
D) ΔG = -220 kJ; nonspontaneous.
76) ______
B) if Q = 1.
D) at the start of the reaction.
77) What is the relationship between ΔG and the ΔG°F for the reaction below?
77) ______
MgF2(s) → Mg2+(aq) + 2 F-(aq)
A) ΔG = {ΔG°f [Mg2+ (aq)] + 2 ΔG°f [F- (aq)] - ΔG°f [MgF2 (s)]} + RT ln ([Mg2+] [F-]2/[MgF2])
B) ΔG = {ΔG°f [Mg2+ (aq)] + 2 ΔG°f [F- (aq)] - ΔG°f [MgF2 (s)]} + RT ln ([Mg2+] [F-])2)
C) ΔG = {ΔG°f [Mg2+ (aq)] + 2 ΔG°f [F- (aq)]} + RT ln ([Mg2+] [F-]2)
D) ΔG = {ΔG°f [Mg2+ (aq)] + 2 ΔG°f [F- (aq)] - ΔG°f [MgF2 (s)]} + RT ln Ksp
78) If Q increases
A) ΔG increases and the reaction becomes more spontaneous.
B) ΔG increases and the reaction becomes less spontaneous.
78) ______
C) ΔG decreases and the reaction becomes more spontaneous.
D) ΔG decreases and the reaction becomes less spontaneous.
79) Which of the following mixtures have components which can be separated by filtration?
A) colloids
B) solutions
C) suspensions
D) all of the above
79) ______
80) Stainless steel is an example of a ________ solution.
A) gas/solid
B) liquid/liquid
C) solid/liquid
80) ______
D) solid/solid
81) In most liquid solutions, the component present in the larger amount is called the
A) dispersed medium.
B) emulsifying agent.
C) solute.
D) solvent.
81) ______
82) The rubbing alcohol sold in drug stores often is composed of 70% isopropyl alcohol and 30%
water. In this solution
A) isopropyl alcohol is the solvent.
B) water is the solvent.
C) both water and isopropyl alcohol are solvents.
D) neither water nor isopropyl alcohol is a solvent.
82) ______
83) Which is not a solution?
A) brass
C) hydrochloric acid
83) ______
B) fog
D) wine
84) For a liquid solution made by dissolving a solid or a gas in a liquid, the
A) liquid is the solute.
B) liquid is the solvent.
C) solute is the component present in the greatest amount.
D) solvent is the component present in the greatest amount.
84) ______
85) Iodine, I2(s), is more soluble in dichloromethane, CH2Cl2(l), than in water because
A) both iodine and dichloromethane have strong ion-dipole interactions.
B) the dipole-dipole forces in dichloromethane are much stronger than the dispersion forces in
iodine.
C) the intermolecular forces are similar in both iodine and dichloromethane.
D) iodine is polar and dichloromethane has a large number of hydrogen bonds.
85) ______
86) For which case would ΔHsoln be expected to be negative?
A) if solute-solute interactions are much greater than solvent-solvent and solute-solvent
interactions
B) if solvent-solvent interactions are much greater than solute-solvent and solute-solute
interactions
C) if solute-solvent interactions are much greater than solvent-solvent and solute-solute
interactions
D) if solute-solvent interactions are the same as solvent-solvent and solute-solute interactions
86) ______
87) KBr does not dissolve well in nonpolar solvents because
A) solute-solute interactions are much larger than solvent-solvent or solute-solvent
interactions.
B) solvent-solvent interactions are much larger than solute-solvent or solute-solute
interactions.
C) solute-solvent interactions are much larger than solvent-solvent or solute-solute
87) ______
interactions.
D) solute-solvent interactions are similar to solvent-solvent and solute-solute interactions.
88) Commercial cold packs often contain solid NH4NO3 and a pouch of water. The temperature of
88) ______
the pack drops as the NH4NO3 dissolves in water. Therefore, for the dissolving of NH4NO3 in
water,
A) ΔHsoln is negative and ΔSsoln may be negative or positive.
B) ΔHsoln is negative and ΔSsoln is positive.
C) ΔHsoln is positive and ΔSsoln may be negative or positive.
D) ΔHsoln is positive and ΔSsoln is positive.
89) When a particular solid begins to dissolve in water, the temperature rises dramatically. For the
dissolving of this solid in pure water
A) ΔHsoln is always negative and ΔSsoln may be negative or positive.
B) ΔHsoln is always negative and ΔSsoln is always positive.
C) ΔHsoln is always positive and ΔSsoln may be negative or positive.
D) ΔHsoln is always positive and ΔSsoln is always positive.
89) ______
90) In the process of dissolving ionic compounds, the cations and anions are separated from the
crystal lattice and surrounded by an ordered shell of solvent molecules. If the solvent is water,
the dissolved ions are said to be
A) halogenated.
B) homogenized.
C) hybridized.
D) hydrated.
90) ______
91) One reason ionic compounds do not dissolve well in nonpolar solvents is that
A) ion-dipole interactions are too large for effective solvation to occur.
B) ion-solvent interactions are not strong enough to solvate the ions in solution.
C) not all cations and anions have the same magnitude of charge and therefore do not form
neutral ion pairs.
D) there are no forces of attraction between ions and nonpolar molecules.
91) ______
92) Which cation in each set is expected to have the larger (more negative) hydration energy?
I Mg2+ or Ba2+
92) ______
II K+ or Al3+
A) Mg2+ in set I and K+ in set II
C) Ba2+ in set I and K+ in set II
B) Mg2+ in set I and Al3+ in set II
D) Ba2+ in set I and Al3+ in set II
93) Which cation in each set would be expected to have the larger (more negative) hydration
energy?
I Fe2+ or Fe3+
II Li+ or NH4+
A) Fe2+ in set I and Li+ in set II
B) Fe2+ in set I and NH4+ in set II
C) Fe3+ in set I and Li+ in set II
D) Fe3+ in set I and NH4+ in set II
93) ______
94) Although there are exceptions, which is most likely to be true for the dissolving of a solid in a
liquid?
A) ΔHsoln is positive.
B) ΔHsoln is negative.
C) ΔSsoln is positive.
D) ΔSsoln is negative.
94) ______
95) When two similar liquids mix to form a solution, the entropy of solution (ΔSsoln) is expected to
be
95) ______
A)
B)
C)
D)
negative.
zero.
positive.
negative at low temperatures but positive at high temperatures.
96) When an ionic solute dissolves in water to form an unsaturated solution, the free energy change
(ΔGsoln) is
A)
B)
C)
D)
96) ______
negative.
zero.
positive.
either A or C, depending on the ionic compound
97) The change in the Gibbs free energy for dissolving more solute in a supersaturated solution is
A) negative.
B) zero.
C) positive.
D) positive at low temperatures and negative at high temperatures.
97) ______
98) The change in the Gibbs free energy for dissolving solute in a saturated solution is
A) negative.
B) zero.
C) positive.
D) positive at low temperatures and negative at high temperatures.
98) ______
99) For the process of dissolving a solid in a liquid, which of the following statements is true?
A) ΔHsoln is always negative and ΔSsoln is usually positive.
B) ΔHsoln is always positive and ΔSsoln is usually negative.
C) ΔHsoln is either positive or negative and ΔSsoln is usually positive.
D) ΔHsoln is either positive or negative and ΔSsoln is usually negative.
99) ______
100) Most gases become less soluble in water as the temperature increases. What can be concluded
100) _____
about the signs of
and
in this case?
A) ΔHsoln is negative and ΔSsoln is negative.
B) ΔHsoln is negative and ΔSsoln is positive.
C) ΔHsoln is positive and ΔSsoln is negative.
D) ΔHsoln is positive and ΔSsoln is positive.
101) Arrange the following compounds in order of their expected increasing solubility in water: KCl,
CH3CH2-O-CH2CH3, CH3CH2CH2CH2-OH, CH3CH2CH2CH2CH3.
101) _____
A) CH3CH2CH2CH2CH3 < KCl < CH3CH2-O-CH2CH3 < CH3CH2CH2CH2-OH
B) KCl < CH3CH2-O-CH2CH3 < CH3CH2CH2CH2-OH < CH3CH2CH2CH2CH3
C) CH3CH2CH2CH2CH3 < CH3CH2-O-CH2CH3 < KCl < CH3CH2CH2CH2-OH
D) CH3CH2CH2CH2CH3 < CH3CH2-O-CH2CH3 < CH3CH2CH2CH2-OH < KCl
102) Which of the following should most favor the solubility of an ionic solid in water?
A) a low lattice energy for the solid and a low hydration energy for its ions
B) a low lattice energy for the solid and a high hydration energy for its ions
C) a high lattice energy for the solid and a low hydration energy for its ions
D) a high lattice energy for the solid and a high hydration energy for its ions
102) _____
103) Which should be least soluble in water?
103) _____
A)
B)
C)
D)
104) What are the major solute-solvent interactions created when KBr dissolves in water?
A) dipole-dipole
B) dispersion
C) hydrogen bonding
D) ion-dipole
104) _____
105) What are the major solute-solvent interactions created when HOCH2CH2OH dissolves in water?
105) _____
A) dipole-dipole
C) hydrogen bonding
B) dispersion
D) ion-dipole
106) Substances with high lattice energies tend to be less soluble than substances with low lattice
energies. On that basis predict the relative aqueous solubility at 20°C, from highest to lowest, of
the following ionic compounds: Ce2(SO4)3, K2SO4, KBr, NaCl.
A) Ce2(SO4)3 > K2SO4 > KBr > NaCl
C) KBr > NaCl > K2SO4 > Ce2(SO4)3
107) Molarity is defined as moles of solute per
A) kilogram of solvent.
C) mole of solvent.
108) Molality is defined as moles of solute per
A) kilogram of solvent.
C) mole of solvent.
106) _____
B) Ce2(SO4)3 > K2SO4 > NaCl > KBr
D) NaCl > KBr > K2SO4 > Ce2(SO4)3
107) _____
B) liter of solution.
D) total moles present.
108) _____
B) liter of solution.
D) total moles present.
109) Which concentration becomes smaller as the temperature is increased from 20°C to 80°C?
A) mass %
B) molality
C) molarity
D) mole fraction
109) _____
110) What is the mole fraction of ethanol in a solution made by dissolving 14.6 g of ethanol, C 2H5OH,
110) _____
in 53.6 g of water?
A) 0.0964
B) 0.106
C) 0.214
D) 0.272
111) What is the molality of ethanol in a solution made by dissolving 14.6 g of ethanol, C 2H5OH, in
53.6 g of water?
A) 0.00591 m
B) 0.272 m
C) 5.91 m
111) _____
D) 272 m
112) What is the mole fraction of I2 in a solution made by dissolving 27.8 g of I2 in 245 g of hexane,
112) _____
C6H14?
A) 0.0371
B) 0.0385
C) 0.0715
D) 0.0770
113) What is the mole fraction of oxygen in a gas mixture that is 22% oxygen and 78% nitrogen by
volume?
113) _____
A) 0.20
B) 0.22
C) 0.25
D) 0.28
114) A solution is prepared by dissolving 17.75 g sulfuric acid, H 2SO4, in enough water to make 100.0
114) _____
mL of solution. If the density of the solution is 1.1094 g/mL, what is the mole fraction H 2SO4 in
the solution?
A) 0.0181
B) 0.0338
C) 0.0350
D) 19.0
115) A solution is prepared by dissolving 17.75 g sulfuric acid, H 2SO4, in enough water to make 100.0
115) _____
mL of solution. If the density of the solution is 1.1094 g/mL, what is the molarity?
A) 0.1775 M H2SO4
B) 0.1810 M H2SO4
C) 1.810 M H2SO4
D) 1.940 M H2SO4
116) A solution is prepared by dissolving 17.75 g sulfuric acid, H 2SO4, in enough water to make 100.0
116) _____
mL of solution. If the density of the solution is 1.1094 g/mL, what is the molality?
A) 0.1775 m H2SO4
B) 0.1810 m H2SO4
C) 1.810 m H2SO4
D) 1.940 m H2SO4
117) A solution is prepared by dissolving 17.75 g sulfuric acid, H 2SO4, in enough water to make
117) _____
exactly 100.0 mL of solution. If the density of the solution is 1.1094 g/mL, what is the weight %
H2SO4 in the solution?
A) 16.00%
B) 18.00%
C) 19.00%
D) 84.00%
118) A solution is prepared by dissolving 171 g of CdCl 2 in enough water to make 250.0 mL of
118) _____
solution. If the density of the solution is 1.556 g/mL, what is the molarity of the solution?
A) 0.440 M
B) 0.684 M
C) 0.933 M
D) 3.73 M
119) A solution is prepared by dissolving 171 g of CdCl 2 in enough water to make exactly 250.0 mL of
119) _____
solution. If the density of the solution is 1.556 g/mL, what is the weight percent of CdCl 2 in the
solution?
A) 7.17%
B) 44.0%
C) 56.0%
D) 68.4%
120) What is the weight percent of vitamin C in a solution made by dissolving 1.30 g of vitamin C,
C6H8O6, in 55.0 g of water?
A) 0.195%
B) 0.242%
C) 2.31%
D) 2.36%
121) What is the weight percent of a caffeine solution made by dissolving 4.35 g of caffeine,
C8H10N4O2, in 75 g of benzene, C6H6?
A) 0.055%
B) 0.058%
C) 5.5%
122) What volume of 0.716 M KBr solution is needed to provide 10.5 g of KBr?
A) 7.52 mL
B) 14.7 mL
C) 63.2 mL
B) 11.1 mL
C) 90.0 mL
122) _____
D) 123 mL
B) 78.0 g
C) 83.3 g
125) To make a 2.0 M solution, one could take 2.00 moles of solute and add
A) 1.00 L of solvent.
123) _____
D) 810 mL
124) How much water must be added to 42.0 g of CaCl 2 to produce a solution that is 35.0 wt% CaCl 2?
A) 56.7 g
121) _____
D) 5.8%
123) What volume of 3.00 M CH3OH solution is needed to provide 0.270 mol of CH 3OH?
A) 1.23 mL
120) _____
124) _____
D) 120 g
125) _____
B) 1.00 kg of solvent.
C) enough solvent to make 1.00 L of solution.
D) enough solvent to make 1.00 kg of solution.
126) To make a 2.00 m solution, one could take 2.00 moles of solute and add
A) 1.00 L of solvent.
B) 1.00 kg of solvent.
C) enough solvent to make 1.00 L of solution.
D) enough solvent to make 1.00 kg of solution.
126) _____
127) What molality of pentane is obtained by dissolving 5.0 g pentane, C 5H12, in 245.0 g hexane,
127) _____
C6H14?
A) 0.020 m
B) 0.024 m
C) 0.28 m
D) 20. m
128) A solution is 2.25% by weight NaHCO3. How many grams of NaHCO3 are in 450.0 g of
solution?
A) 0.500 g
B) 10.1 g
C) 200 g
128) _____
D) 225 g
129) How many grams of KBr are required to make 650. mL of a 0.115 M KBr solution?
A) 0.628 g
B) 5.65 g
C) 8.90 g
D) 74.8 g
129) _____
130) What is the molality of a glucose solution prepared by dissolving 18.0 g of glucose, C 6H12O6, in
130) _____
125.9 g of water?
A) 7.94 × 10-4 m
B) 0.143 m
C) 0.695 m
D) 0.794 m
131) Aqueous solutions of 30% (by weight) hydrogen peroxide, H 2O2, are used to oxidize metals or
131) _____
organic molecules in chemical reactions. Given that the density of the solution is 1.11 g/mL,
calculate the molarity.
A) 0.794 M
B) 6.78 M
C) 9.79 M
D) 12.6 M
132) Aqueous solutions of 30.0% (by weight) hydrogen peroxide, H 2O2, are used to oxidize metals or
132) _____
organic molecules in chemical reactions. Calculate the molality of this solution.
A) 0.974 m
B) 6.78 m
C) 9.79 m
D) 12.6 m
133) Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution. The density
of the solution is 1.53 g/mL. Calculate the molarity of this sodium hydroxide solution.
A) 0.450 M
B) 19.1 M
C) 25.0 M
D) 125. M
133) _____
134) Sodium hydroxide is available commercially as a 50.0% by weight aqueous solution. Calculate
the molality of this sodium hydroxide solution.
A) 0.450 m
B) 19.1 m
C) 25.0 m
D) 125. m
134) _____
135) A 1.30 M solution of CaCl2 in water has a density of 1.11 g/mL. What is the molality?
135) _____
A) 1.17 m CaCl2
B) 1.25 m CaCl2
C) 1.35 m CaCl2
D) 1.44 m CaCl2
136) A 3.17 m solution of CaCl2 in water has a density of 1.24 g/mL. What is the molarity?
A) 2.56 M CaCl2
B) 2.91 M CaCl2
C) 3.50 M CaCl2
D) 3.93 M CaCl2
137) A 2.00 M solution of CaCl2 in water has a density of 1.17 g/mL. What is the mole fraction of
CaCl2?
A) 0.0348
B) 0.0360
C) 0.0366
136) _____
D) 0.0380
137) _____
138) _____
138) A solution of LiCl in water has XLiCl = 0.0500. What is the molality?
A) 2.60 m LiCl
B) 2.77 m LiCl
C) 2.92 m LiCl
D) 5.26 m LiCl
139) A solution of LiCl in water is 18.0 wt% LiCl. What is the mole fraction of LiCl?
A) 0.0853
B) 0.0933
C) 0.425
D) 4.56
139) _____
140) At 25.0°C, a solution has a concentration of 3.179 M and a density of 1.260 g/mL. The density of
the solution at 50.0°C is 1.249 g/mL. What is the molarity of the solution at 50.0°C?
A) 2.545 M
B) 3.151 M
C) 3.179 M
D) 3.230 M
140) _____
141) A saturated solution is defined as
A) a concentrated solution.
B) a solution that is in equilibrium with pure solvent.
C) a solution than is in equilibrium with undissolved solute.
D) a solution that is in equilibrium with both pure solvent and undissolved solute.
141) _____
142) Which of the following does not affect the solubility of a solute in a given solvent?
A) polarity of the solute
B) polarity of the solvent
C) rate of stirring
D) temperature of the solvent and solute
142) _____
143) Which of the following statements is true for a supersaturated solution?
A) The solute in the solution is at equilibrium with undissolved solute.
B) The solution contains more than the equilibrium amount of solute.
C) The solution is stable and the solute will not precipitate.
D) A supersaturated solution is more than 50% solute by mass.
143) _____
144) In general, as the temperature increases, the solubility of gases in water ________ and the
solubility of most solids in water ________.
A) decreases, decreases
B) decreases, increases
C) increases, decreases
D) increases, increases
144) _____
145) The solubility of gaseous solutes in liquid solvents is greater when the
A) external pressure over the solution is increased.
B) external pressure is decreased.
C) partial pressure of the gas above the solution is increased.
D) partial pressure of the solvent is increased.
145) _____
146) In which case should CO2(g) be more soluble in water?
146) _____
A) The total pressure is 5 atm and the partial pressure of CO2 is 1 atm.
B) The total pressure is 3 atm and the partial pressure of CO 2 is 2 atm.
C) The total pressure is 1 atm and the partial pressure of CO 2 is 0.03 atm.
D) The total pressure is 1 atm and the partial pressure of CO 2 is 0.5 atm.
147) The Henry's Law constant of methyl bromide, CH3Br, is k = 0.159 mol/(L ∙ atm) at 25°C. What is
147) _____
the solubility of methyl bromide in water at 25°C and at a partial pressure of 250. mm Hg?
A) 0.0523 mol/L
B) 0.329 mol/L
C) 0.483 mol/L
D) 39.8 mol/L
148) The solubility of argon in water at 25°C is 0.0150 mol/L. What is the Henry's Law constant for
argon if the partial pressure of argon in air is 0.00934 atm?
A) 1.40 × 10-4 mol/(L ∙ atm)
B) 0.623 mol/(L ∙ atm)
148) _____
C) 1.61 mol/(L ∙ atm)
D) 4.10 mol/(L ∙ atm)
149) Which of the following is not an application of colligative properties?
A) adding silver to mercury to lower the vapor pressure of mercury
B) desalinating sea water by reverse osmosis
C) melting snow by application of salt
D) reduced boiling points of pure liquids at increased altitudes
149) _____
150) A solution is prepared by dissolving 40.0 g of sucrose, C 12H22O11, in 250. g of water at 25°C.
150) _____
What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?
A) 0.198 mm Hg
B) 20.5 mm Hg
C) 23.6 mm Hg
D) 24.0 mm Hg
151) A KCl solution is prepared by dissolving 40.0 g KCl in 250.0 g of water at 25°C. What is the
vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg?
A) 20.5 mm Hg
B) 22.1 mm Hg
C) 22.9 mm Hg
D) 25.5 mm Hg
151) _____
152) At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm
Hg, respectively. Calculate the total vapor pressure over a solution of benzene and toluene with
Xbenzene = 0.600.
152) _____
A) 110 mm Hg
B) 121 mm Hg
C) 133 mm Hg
D) 242 mm Hg
153) At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm
Hg, respectively. Calculate the mole fraction of benzene in the vapor phase over a solution of
benzene and toluene with Xbenzene = 0.600.
A) 0.600
B) 0.678
C) 0.756
D) 0.823
154) How many grams of sucrose, C12H22O11, must be added to 500. g of water at 100°C to change
the vapor pressure to 752 mm Hg?
A) 0.295 g
B) 5.32 g
C) 10.6 g
153) _____
154) _____
D) 101 g
155) If one mole of each is dissolved in 1.00 L of water, which will lower the vapor pressure the most?
A) C12H22O11
B) NaNO3
C) C3H7OH
D) MgCl2
155) _____
156) When 2.36 g of a nonvolatile solute is dissolved in 100 g of solvent, the largest change in freezing
point will be achieved when the solvent is
A) benzene, Kf = 5.07.
156) _____
B) camphor, Kf = 37.8.
C) chloroform, Kf = 4.70.
D) All are expected to have the same freezing point.
157) A 0.50 m solution of which solute has the largest van't Hoff factor?
A) CaCl2
B) K3PO4
C) LiCO3
157) _____
D) NaNO3
158) A 0.020 m aqueous solution containing which solute will have the lowest freezing point?
A) LiCl
B) NaCl
C) KCl
D) All will have approximately the same freezing point.
158) _____
159) Which of the following solutions will have the lowest freezing point?
A) 0.0100 m NaCl
B) 0.0100 m Li2SO4
159) _____
C) 0.035 m CH3CH2CH2OH
D) 0.015 m MgCl2
160) Which of the following pairs of solutions have roughly the same boiling point elevation?
A) 0.100 m C6H12O6 and 0.0333 m CuCl2
B) 0.100 m NaCl and 0.100 m C6H12O6
C) 0.200 m NaCl and 0.300 m Na2SO4
D) 0.100 m KCl and 0.0500 m MgBr2
161) What is the expected freezing point of a 0.50 m solution of Na2SO4 in water? Kf for water is
1.86°C/m.
A) -0.93°C
B) -1.9°C
C) -2.8°C
A) -1.05°C
B) 1.05°C
C) 4.45°C
D) 6.54°C
B) -0.279°C
C) -0.559°C
100. g of benzene has a normal boiling point of
B) 500 amu
A) -0.55°C
D) 20,000 amu
165) _____
and
B) -2.0°C
C) -3.6°C
D) -7.3°C
166) A solution of 0.2113 g of water dissolved in 25.0 g of a solvent freezes at 11.5°C below the
freezing point of the solvent. What is Kf for this solvent?
A) 0.735°C/m
164) _____
for benzene, C6H6.
C) 2000 amu
165) An aqueous solution has a normal boiling point of 102.0°C. What is the freezing point of this
solution? For water Kb is
163) _____
D) -0.838°C
164) The normal boiling point of pure benzene is found to be 80.10°C. What is the approximate
molecular weight of a nonionizing substance if a solution of 3.55 g of the substance dissolved in
A) 20 amu
162) _____
and the freezing point is 5.50°C for benzene.
163) What is the freezing point of a solution of 1.43 g MgCl 2 in 100 g of water? Kf for water is
1.86°C/m for water.
A) -0.0279°C
161) _____
D) -6.5°C
162) Calculate the freezing point of a solution of 20.0 g methyl salicylate, C 7H6O2, dissolved in 800. g
of benzene, C6H6. Kf for benzene is
160) _____
B) 1.36°C/m
C) 5.39°C/m
166) _____
D) 24.5°C/m
167) A 0.51 m aqueous solution of an unknown solute has a boiling point elevation of 0.62°C. The
boiling point elevation of a 0.51 m solution of a nonionizing molecular solute in water is 0.26°C.
How many moles of particles are formed per mole of solute when the unknown solute is
dissolved in water?
A) 1.4
B) 2.0
C) 2.4
D) 3.0
167) _____
168) An aqueous CsCl solution is 8.00 wt% CsCl and has a density of 1.0643 g/mL at 20°C. What is the
boiling point of this solution? Kb = 0.51°C/m for water.
168) _____
A) 100.27°C
B) 100.53°C
C) 103.8°C
D) 104.3°C
169) Chloroform has a boiling point of 61.1°C and dichloromethane has a boiling point of 40.0°C.
When 0.100 mol of dichloromethane is added to 0.900 mol of chloroform, the resulting solution
will have a boiling point
A) between 40.0°C and 61.1°C, but closer to 61.1°C.
B) between 40.0°C and 61.1°C, but closer to 40.0°C.
C) greater than 61.1°C.
D) less than 40.0°C.
169) _____
170) Two aqueous solutions, A and B, are separated by a semipermeable membrane. The osmotic
pressure of
solution 170)
A
immedia
tely
begins to
decrease.
Which of
the
followin
g
statemen
ts is
true?
A) Solvent molecules are moving from solution B into solution A.
B) The initial osmotic pressure of solution B is greater than that of solution A.
C) The solvent molecules are moving from the solution of higher osmotic pressure to that of
lower osmotic pressure.
D) Both B and C are true statements.
____
_
171) Red blood cells are placed into pure water. Which of the following statements is true?
A) Water molecules flow out of the red blood cells, causing them to collapse.
B) Water flows into the red blood cells, causing them to swell and burst.
C) The osmotic pressure of the cell contents increases, causing the cells to burst.
D) The osmotic pressure inside the cells equals the osmotic pressure outside.
171) _____
172) How will the osmotic pressure of an aqueous solution change as evaporation occurs?
A) The osmotic pressure will increase.
B) The osmotic pressure will not change.
C) The osmotic pressure will decrease.
D) The osmotic pressure will increase or decrease until it equals the vapor pressure of water.
172) _____
173) Assuming that sea water is a 3.5 wt % solution of NaCl in water, calculate its osmotic pressure at
20°C. The density of a 3.5% NaCl solution at 20°C is 1.023 g/mL.
A) 1.0 atm
B) 15 atm
C) 29 atm
D) 100 atm
173) _____
174) A solution is made by dissolving 13 g of sucrose, C12H22O11, in 117 g of water, producing a
174) _____
solution with a volume of 125 mL at 20°C. What is the expected osmotic pressure at 20°C?
A) 7.3 atm
B) 10 atm
C) 14 atm
D) 58 atm
175) The average osmotic pressure of blood is about 7 atm. Therefore
A) the average blood pressure is about 7 atm.
B) the average pressure inside the body is about 7 atm above the external pressure.
C) a pressure of about 7 atm would be required to prevent osmosis if blood is in contact with
pure water across a semipermeable membrane.
D) All of the above are true.
175) _____
176) When 0.500 g of vitamin K is dissolved in 10.0 g of camphor (Kf = 40.0°C/m), the freezing point of
176) _____
the solution is 4.43°C lower than that of pure camphor. Assuming vitamin K is a nonelectrolyte
in camphor, calculate its molar mass.
A) 0.451 g/mol
B) 55.4 g/mol
C) 451 g/mol
D) 3.54 × 104 g/mol
177) When ethylene glycol, HOCH2CH2OH, is added to the water in an automobile radiator, the
177) _____
effect is to
A) lower the boiling point and lower the freezing point.
B) lower the boiling point and raise the freezing point.
C) raise the boiling point and lower the freezing point.
D) raise the boiling point and raise the freezing point.
178) The coolant in automobiles is often a 50/50 % by volume mixture of ethylene glycol,
HOCH2CH2OH, and water. At 20°C, the density of ethylene glycol is 1.1088 g/mL and the
178) _____
density of water is 0.9982 g/mL. Assuming that the volumes are additive, what is the expected
freezing point of a 50/50(v/v)% ethylene glycol/water solution? Kf = 1.86°C/m for water.
A) -16°C
B) -17°C
C) -30°C
D) -33°C
179) Naproxen is a commercially important anti-inflammatory agent that can be isolated from the
thyroid gland. A solution of 1.138 g of naproxen in 25.00 g benzene has an osmotic pressure of
4.00 atm at 20°C. The density of benzene is 0.8787 g/mL at this temperature. Calculate the molar
mass of naproxen, assuming it remains intact upon dissolution and the density of the solution
equals the density of pure benzene.
A) 176 g/mol
B) 230 g/mol
C) 307 g/mol
D) 3.80 × 105 g/mol
179) _____
180) A solution of 62.4 g of insulin in enough water to make 1.000 L of solution has an osmotic
pressure of 0.305 atm at 25°C. Based on these data, what is the molar mass of insulin?
A) 621 g/mol
B) 5000 g/mol
C) 7570 g/mol
D) 71,900 g/mol
180) _____
181) Which drawing above represents the system with the highest entropy?
A) drawing (a)
B) drawing (b)
C) drawing (c)
181) _____
D) drawing (d)
182) Which drawing above represents the system with the lowest entropy?
A) drawing (a)
B) drawing (b)
C) drawing (c)
D) drawing (d)
182) _____
183) Which drawing above represents the system with the second lowest entropy?
A) drawing (a)
B) drawing (b)
C) drawing (c)
D) drawing (d)
183) _____
184) Which drawing above represents the system with the second highest entropy?
A) drawing (a)
B) drawing (b)
C) drawing (c)
D) drawing (d)
184) _____
Arrows in the energy diagram below represent enthalpy changes occurring in the exothermic formation of a solution:
ΔHsoln = enthalpy of solution
ΔHsolute-solute = enthalpy change involving solute-solute interactions
ΔHsolute-solvent = enthalpy change involving solute-solvent interactions
ΔHsolvent-solvent = enthalpy change involving solvent-solvent interactions
185) Which arrow represents ΔHsoln?
A) arrow (a)
B) arrow (b)
186) Which arrow represents ΔHsolute-solvent?
A) arrow (a)
B) arrow (b)
185) _____
C) arrow (c)
D) arrow (d)
186) _____
C) arrow (c)
D) arrow (d)
187) Which arrows represent ΔHsolute-solute and ΔHsolvent-solvent?
A) arrow (a) and arrow (b)
B) arrow (a) and arrow (c)
C) arrow (a) and arrow (d)
D) arrow (c) and arrow (d)
187) _____
Arrows in the energy diagram below represent enthalpy changes occurring in the endothermic formation of a solution:
ΔHsoln = enthalpy of solution
ΔHsolute-solute = enthalpy change involving solute-solute interactions
ΔHsolute-solvent = enthalpy change involving solute-solvent interactions
ΔHsolvent-solvent = enthalpy change involving solvent-solvent interactions
188) Which arrow represents ΔHsoln?
A) arrow (a)
B) arrow (b)
189) Which arrow represents ΔHsolute-solvent?
A) arrow (a)
B) arrow (b)
188) _____
C) arrow (c)
D) arrow (d)
189) _____
C) arrow (c)
D) arrow (d)
190) Which arrows represent ΔHsolute-solute and ΔHsolvent-solvent?
A) arrow (a) and arrow (b)
B) arrow (a) and arrow (c)
C) arrow (a) and arrow (d)
D) arrow (c) and arrow (d)
191) Which ion-dipole interaction results in the larger (more negative) hydration energy?
190) _____
____
_
191)
A) diagram (a)
B) diagram (b)
C) diagram (c)
D) diagram (d)
192) Which ion-dipole interaction results in the larger (more negative) hydration energy?
A) diagram (a)
B) diagram (b)
C) diagram (c)
192) _____
D) diagram (d)
193) Drawing (1) shows a system in which an equilibrium exists between dissolved and undissolved
gas particles at P = 1 atm. According to Henry's law, if the pressure is increased to 2 atm and
equilibrium is restored, which drawing (2)-(5) best represents the equilibrium at 2 atm?
193) _____
A) drawing (2)
B) drawing (3)
C) drawing (4)
D) drawing (5)
194) Drawing (1) shows a system in which an equilibrium exists between dissolved and undissolved
gas particles at P = 1 atm. According to Henry's law, if the pressure is decreased to 0.5 atm and
equilibrium is restored, which drawing (2)-(5) best represents the equilibrium at 0.5 atm?
A) drawing (2)
B) drawing (3)
C) drawing (4)
D) drawing (5)
195) Drawing (1) shows the equilibrium vapor pressure of a pure liquid. Which drawing (2)-(5)
represents the equilibrium vapor pressure when a nonvolatile solute is dissolved in the liquid?
A) drawing (2)
B) drawing (3)
C) drawing (4)
194) _____
D) drawing (5)
196) Drawings (1) and (2) show the equilibrium vapor pressures of two pure liquids. Which drawing
(3)-(6) represents the equilibrium vapor pressure of a solution made by mixing equal moles of
each liquid?
195) _____
____
_
196)
A) drawing (3)
B) drawing (4)
C) drawing (5)
D) drawing (6)
The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a
nonvolatile solute dissolved in this solvent.
197) Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved
in the solvent?
A) Curve (a) is the solvent and the vapor pressure decreases.
B) Curve (a) is the solvent and the vapor pressure increases.
C) Curve (b) is the solvent and the vapor pressure decreases.
D) Curve (b) is the solvent and the vapor pressure increases.
197) _____
198) Which curve is the solvent and what happens to the boiling point when the solute is dissolved in
the solvent?
A) Curve (a) is the solvent and the boiling point decreases.
B) Curve (a) is the solvent and the boiling point increases.
C) Curve (b) is the solvent and the boiling point decreases.
D) Curve (b) is the solvent and the boiling point increases.
198) _____
199) The following diagram shows a close-up view of the vapor pressure curves for two pure liquids
and two different solutions composed of these two liquids. Which curves represent pure liquids
and which curves represent the solutions?
199)
_____
A)
B)
C)
D)
Curves (a) and (b) are the pure liquids and curves (c) and (d) are the solutions.
Curves (a) and (c) are the pure liquids and curves (b) and (d) are the solutions.
Curves (a) and (d) are the pure liquids and curves (b) and (c) are the solutions.
Curves (c) and (d) are the pure liquids and curves (a) and (b) are the solutions.
200) Drawing (1) shows a nonequilibrium system comprised of pure water separated from an
aqueous solution by a semipermeable membrane. Shaded spheres represent solute particles and
unshaded spheres represent water molecules. Which drawing (2)-(5) represents this system after
equilibrium is reached?
A) drawing (2)
B) drawing (3)
C) drawing (4)
D) drawing (5)
201) Two beakers, one with pure water (light gray) and the other with an aqueous solution of KBr
(dark gray), are placed in a closed container represented by drawing (a). Which of the drawings
(a)-(d) represents what the beakers will look like after a substantial amount of time has passed?
A) drawing (a)
B) drawing (b)
C) drawing (c)
200) _____
201) _____
D) drawing (d)
A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp =
decane (bp = 126°C) is shown.
and
202) Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane, what
region of the diagram corresponds to liquid?
A) region a
B) region b
C) region c
D) regions a and c
202) _____
203) Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane, what
region of the diagram corresponds to vapor?
A) region a
B) region b
C) region c
D) regions a and c
203) _____
A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp =
decane (bp = 126°C) is shown.
and
204) Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane, at
what approximate temperature will the mixture begin to boil?
A) temperature at point a
B) temperature at point b
C) temperature at point d
D) temperature at point f
204) _____
205) Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane, what
is the liquid composition at the boiling point?
A) 100% decane
B) composition at point b
C) composition at point c
D) composition at point e
205) _____
206) Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane, what
is the vapor composition at the boiling point?
A) 100% decane
B) composition at point b
C) composition at point c
D) composition at point e
206) _____
207) Assume that the vapor at point c is condensed and reboiled. What is the liquid composition of
the condensed vapor prior to reboiling?
A) 100% decane
B) composition at point b
C) composition at point d
D) composition at point e
207) _____
208) Assume that the vapor at point c is condensed and reboiled. What is the vapor composition
during reboiling?
A) 100% decane
B) composition at point b
C) composition at point c
D) composition at point e
208) _____
209) Assume that the vapor at point c is condensed and reboiled. What is the boiling point?
A) temperature at point b
B) temperature at point c
C) temperature at point d
D) temperature at point f
209) _____
210) What is the approximate boiling temperature of a mixture that is 0.70 XA and 0.30 XB?
210) _____
A) 50°C
B) 75°C
C) 95°C
D) 100°C
211) What is the approximate vapor composition above a boiling solution that is 0.70 XA and 0.30 XB
211) _____
?
A) 0.70 XA, 0.30 XB
C) 0.30 XA, 0.70 XB
B) 0.50 XA, 0.50 XB
D) 0 XA, 1.00 XB
212) What is the approximate boiling temperature of the liquid formed from the condensation of the
vapor above a boiling solution that is 0.70 XA and 0.30 XB?
A) 50°C
B) 55°C
C) 90°C
D) 100°C
213) At 80°C, pure liquid A has a vapor pressure of 700 mm Hg and pure liquid B has a vapor
pressure of 940 mm Hg. What is XA for a solution of A and B with a normal boiling point of
A) 0.25
C) 0.75
212) _____
B) 0.50
D) A solution of A and B cannot boil at
80°C.
213) _____
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
C
D
A
A
B
B
B
C
D
A
C
B
A
C
B
D
C
B
C
C
A
B
B
A
D
D
C
C
D
C
D
C
B
A
B
C
C
C
B
D
D
B
B
B
C
B
C
B
B
B
A
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)
64)
65)
66)
67)
68)
69)
70)
71)
72)
73)
74)
75)
76)
77)
78)
79)
80)
81)
82)
83)
84)
85)
86)
87)
88)
89)
90)
91)
92)
93)
94)
95)
96)
97)
98)
99)
100)
101)
102)
103)
C
A
A
B
C
C
C
B
D
B
C
A
C
C
B
A
D
C
C
C
A
C
C
C
B
B
B
C
D
D
A
B
B
C
C
A
D
A
D
B
B
C
C
C
A
C
B
C
A
D
B
A
104)
105)
106)
107)
108)
109)
110)
111)
112)
113)
114)
115)
116)
117)
118)
119)
120)
121)
122)
123)
124)
125)
126)
127)
128)
129)
130)
131)
132)
133)
134)
135)
136)
137)
138)
139)
140)
141)
142)
143)
144)
145)
146)
147)
148)
149)
150)
151)
152)
153)
154)
155)
D
C
C
B
A
C
A
C
A
B
B
C
D
A
D
B
C
C
D
C
B
C
B
C
B
C
D
C
D
B
C
C
B
C
C
A
B
C
C
B
B
C
B
A
C
D
C
B
C
D
D
D
156)
157)
158)
159)
160)
161)
162)
163)
164)
165)
166)
167)
168)
169)
170)
171)
172)
173)
174)
175)
176)
177)
178)
179)
180)
181)
182)
183)
184)
185)
186)
187)
188)
189)
190)
191)
192)
193)
194)
195)
196)
197)
198)
199)
200)
201)
202)
203)
204)
205)
206)
207)
B
B
D
D
A
C
C
D
C
D
D
C
B
A
A
B
A
C
A
C
C
C
D
B
B
C
A
D
B
D
C
A
D
C
A
A
C
D
C
B
C
A
B
C
A
B
C
A
B
B
C
C
208)
209)
210)
211)
212)
213)
D
C
B
C
B
C