Questions 1 – 13 cover material from Exam 1
1.
2.
Which intermolecular forces are present in H2Te(l)?
A.
dispersion only
C.
B.
dispersion and dipole-dipole
D.
Assuming all compounds are in the liquid phase, which of the following has the
compound with the greater surface tension listed first?
A.
B.
3.
benzene (C6H6), H2O
CH3OCH3, CH3CH2OH
C.
D.
CH3Cl, CH4
Br2, I2
Antimony has a normal boiling point of 1860 K and ΔHvap = 77.14 kJ/mol. What happens
to the vapor pressure of antimony when the temperature is increased to 1950 K?
A.
B.
C.
D.
4.
dispersion, dipole-dipole, and hydrogen
bonding
ion-dipole only
The vapor pressure exceeds 760 torr.
The vapor pressure is 760 torr.
The vapor pressure falls between 760 and 380 torr.
The vapor pressure falls below 380 torr.
Sublimation is
A. the phase transition from solid to liquid.
B. the phase transition from gas to solid.
C. the phase transition from liquid to gas.
D. the phase transition from solid to gas.
5.
How much heat is required to convert 9.01 g of ice at −100.0 °C to liquid water at 0.0 °C?
Specific heat, ice = 2.09 J/g.°C
Specific heat, water = 4.18 J/g.°C
Specific heat, steam = 2.01 J/g.°C
Heat of vaporization, water = 40.7 kJ/mol
Heat of fusion, water = 6.02 kJ/mol
A.
B.
6.
4.89 kJ
80.3 kJ
C.
D.
1080 kJ
13.4 kJ
What is the density of chromium (52.00 g/mol), which crystallizes in a body-centered
cubic unit cell with a volume of 2.41 × 10−23 cm3?
A.
B.
4.5 g/cm3
9.27 g/cm3
C.
D.
12.1 g/cm3
7.17 g/cm3
7.
What type of crystalline solid has a low melting point and is held together by dispersion
forces only?
A.
molecular solid
C. ionic solid
B.
nonbonding atomic solid
D. network covalent solid
8.
Which of the following compounds is most soluble in hexane, C6H14?
A.
NH3
C. KI
B.
H2O
D. CCl4
9.
Which statement best describes the unique property of a supersaturated solution?
A.
B.
C.
D.
A supersaturated solution must have more solute than solvent.
A supersaturated solution can dissolve more solute.
A supersaturated solution has more solute dissolved than predicted by the
solubility.
A supersaturated solution has a precipitated solute in equilibrium with the
dissolved solute.
10. Oxygen is most soluble in water at
A.
high temperature and high partial pressure of oxygen.
B.
low temperature and high partial pressure of oxygen.
C.
high temperature and low partial pressure of oxygen.
D.
low temperature and low partial pressure of oxygen.
11. A 12 m HNO3 aqueous solution contains
A.
B.
C.
D.
12 g of HNO3 in 1.00 L of solution.
12 g of HNO3 in 100 mL of water.
12 mol of HNO3 in 1.00 kg of solution.
12 mol of HNO3 in 1.00 kg of water.
12. What is the freezing point of an aqueous 2.23 m ethylene glycol solution? The freezing
point constant, Kf, of water is 1.86 °C/m.
A.
1.14 °C
C. −4.15 °C
B.
5.48 °C
D. −2.23 °C
13. Which of the following 0.100 M solutions will have the lowest osmotic pressure?
A.
CaCl2
C. (NH4)3PO4
B.
C6H12O6
D. NaNO3
Questions 14 – 26 cover material from Exam 2
14. If H2(g) appears at a rate of 1.00 M/s at a particular moment in the reaction below, what
is the rate of CH4(g) consumption at the same instant?
CH4(g) + 2 H2S(g) → CS2(g) + 4 H2(g)
A.
B.
0.250 M/s
0.500 M/s
C.
D.
2.50 M/s
3.00 M/s
15. For the reaction
2 NO(g) + Cl2(g) → 2 NOCl(g)
rate = k [NO]2[Cl2]
what is the effect on the rate if the concentration of NO is tripled and that of Cl2 is
doubled?
A.
B.
C.
D.
The rate will increase by a factor of eighteen.
The rate will increase by a factor of six.
The rate will increase by a factor of twenty-four.
The rate will decrease by a factor of twelve.
16. The decomposition of
N2O(g) on a Pt surface
follows zero-order kinetics.
2 N2O(g) → 2 N2(g) + O2(g)
Which curve accurately
graphs the relationship
between rate and
concentration for this
reaction?
A.
B.
Reaction 1
Reaction 2
C.
D.
Reaction 3
Reaction 4
17. When the Kelvin temperature of a reaction is reduced by half, the value of the rate
constant, k
A.
B.
C.
D.
doubles.
increases, but doesn’t necessarily double.
decreases by half.
decreases, but not necessarily by half.
18. The reaction, 2 Cl(g) → Cl2(g), is known to be catalyzed by N2(g). The following
mechanism has been proposed for the catalyzed reaction.
Step 1
Step 2
N2 + Cl ⇌ N2Cl
N2Cl + Cl → Cl2 + N2
fast
slow
What is the rate law for the reaction, 2 Cl(g) → Cl2(g)?
A.
B.
rate = k[N2Cl]2
rate = k[N2][Cl]2
C.
D.
rate = k[Cl]2
rate = k[Cl]
19. Which one of the following is the equilibrium constant expression, Kc, for the reaction
below?
2 ZnS(s) + 3O2(g) ⇌ 2 ZnO(s) + 2 SO2(g)
A.
B.
[SO ]2
2
[O ]3
2
[O ]2
2
[SO ]3
2
C.
2[ ZnO] + 2[SO 2 ]
2[ ZnS] + 3[O 2 ]
D.
[ ZnS ][O 2 ]2
[ ZnO] [SO 2 ]3
20. What is Kp for the overall reaction that converts propane (C3H8) and steam to carbon
dioxide and hydrogen gas (H2) at 1200 K given the following information?
C3H8(g) + 3 H2O(g) ⇌ 3 CO(g) + 7 H2(g)
CO(g)+ H2O(g) ⇌ CO2(g) + H2(g)
A.
B.
8.3 × 1015
1.2 × 1014
C.
D.
2.7 × 1015
3.5 × 1016
Kp = 8.2 × 1015
Kp = 0.69
21. Which way will the reaction proceed, given the following initial concentrations?
[C2H4] = 0.010 M, [H2O] = 0.200 M, [C2H5OH] = 0.200 M
C2H4(g) + H2O(g) ⇌ C2H5OH(g)
A.
B.
to the left because Q > K
to the left because Q < K
Kc = 7.4 × 102 at 250 K
C.
D.
to the right because Q > K
to the right because Q < K
22. For the following reaction at 298 K, Kp = 6.70.
2 NO2(g) ⇌ N2O4(g)
At equilibrium, the partial pressure of NO2 is 0.12 atm. Determine the partial pressure of
N2O4 at equilibrium.
A.
B.
15 atm
0.096 atm
C.
D.
1.2 atm
0.16 atm
23. Given the following reaction, initially at equilibrium, which change will cause the
greatest shift in the equilibrium to favor product formation?
3 C(s) + 4 H2(g) ⇌ C3H8(g)
A.
B.
double the mass of C
decrease the pressure of the container
ΔHrxn = ‒105 kJ/mol
C. remove H2
D. lower the temperature
24. In the following reaction, NH3 is behaving as a(n) _______________________.
H2PO4–(aq) + NH3(aq) → HPO42–(aq) + NH4+(aq)
A.
B.
Brønsted-Lowry acid
Brønsted-Lowry base
C.
D.
Arrhenius acid
Arrhenius base
25. Which one of the following acids has the lowest percent ionization at 0.100 M?
A.
HCN, Ka = 4.9 × 10−10
C. HC9H7O4, Ka = 3.3 × 10−4
B.
HC2H3O2, Ka = 1.8 × 10−5
D.
HCl, Ka >> 1
26. Which 0.100 M solution will have the highest pH?
A.
ketamine, C13H16ClNO, Kb = 3.0 × 10−7
B.
ammonia, NH3, Kb = 1.76 × 10−5
C.
piperidine, C5H10NH, Kb = 1.33 × 10−3
D.
pyridine, C5H5N, Kb = 1.70 × 10−9
Answer Key:
1. B
2. C
3. A
4. D
5. A
6. D
7. B
8. D
9. C
10. B
11. D
12. C
13. B
14. A
15. A
16. A
17. D
18. B
19. A
20. C
21. C
22. B
23. D
24. B
25. A
26. C