Multiple Choice
1.
2.0 L of nitrogen gas expands against a constant pressure of 1.0 atm and does work equals to
650 J. What will be the final volume of the gas (in L)?
A)
2.
D)
5.7
0.030
B)
0.102
C)
0.121
D)
0.142
4.4×10-4M
B)
5.3×10-4M
C)
6.2×10-4M
D)
4.4×10-5M
350
B)
388
C)
192
D)
180
66.8
B)
75.8
C)
81.4
D)
92.6
A solution containing 0.750 g of an organic polymer in 150.0 ml of an organic solvent was
found to have an osmotic pressure of 5.2 mmHg at 27oC. Determine (in g mol-1) the molar
mass of the polymer:
A)
7.
6.4
What is the molar mass (in g. mol-1) of an organic non-volatile compound if 0.85 g of it
depresses the freezing point of 100 g of benzene by 0.47oC? (Kf of benzene is 5.12oC/m).
A)
6.
C)
At 20oC, the vapor pressure of pure water is 17.5 torr, while that of 200.0 g of a non-volatile
solute in 350 g of water is 17.0 torr. Calculate the molar mass of this solute in g mol-1.
A)
5.
7.2
The Henry's law constant for nitrogen gas at 25oC is 6.810-4 mol/L.atm. What is the
concentration of nitrogen dissolved in water under atmospheric conditions knowing that the
mole fraction of nitrogen is 0.78?
A)
4.
B)
An ideal solution of 3.0 mol heptane and 5.0 mol octane have a vapor pressure 0.071 atm at
40oC. Knowing that the vapor pressure of pure octane at 40oC is 0.041 atm. What will be the
vapor pressure of pure heptane at 40oC (in atm)?
A)
3.
8.4
2.4104
B)
2.2104
C)
2.0104
D)
1.8104
For the reaction:
BrO3– + 5Br– + 6H+  3Br2 + 3H2O
The value of –[Br-]/t = 7.510-2 mol L-1 s-1 at a particular time. What will be the value of
[Br2]/t at the same instant (in mol L-1 s-1)?
A)
8.
1.2510-2
B)
1.510-2
C)
4.510-2
D)
1.2510-1
Nitric oxide reacts with chlorine to form nitrosyl chloride.
NO + 1/2Cl2  NOCl
Use the following data to determine the rate law (rate equation) for this reaction:
Experiment
[NO]
[Cl2]
Initial rate
1
0.22
0.064
0.96 mol L-1 min-1
2
0.66
0.064
8.64 mol L-1 min-1
3
0.22
0.032
0.48 mol L-1 min-1
A)
C)
Rate = k [NO]2 [Cl2]2
Rate = k [NO] [Cl2]1/2
B)
D)
-1-
Rate = k [NO]2 [Cl2]1/2
Rate = k [NO]2 [Cl2]
9.
At 25oC, the rate constant for the first order decomposition of a pesticide solution is 6.410-3
min-1. If the starting concentration of pesticide is 0.0314 mol L-1. What concentration (in
mol L-1) will remain after 62.0 min at 25oC?
A)
10.
0.0131
C)
0.0191
D)
0.0211
59
B)
66
C)
74
D)
88
Which of the following would alter the value of the rate constant (k) for the reaction?
2A + B  products
A)
B)
C)
D)
12.
B)
The reaction 2A  B is first order in A with a rate constant of 2.810-2 s-1. How long (in
seconds) will it take for A to decrease from 0.88 mol L-1 to 0.14 mol L-1?
A)
11.
0.011
Increasing the concentration of A only.
Increasing the concentration of B only.
Increasing the concentration of both A and B.
Increasing the temperature.
Which is the correct equilibrium constant expression for the following reaction?
Fe2O3(s) + 3H2(g) ⇌ 2Fe(s) + 3H2O(g)
A)
C)
13.
Kc = [H2O]3 / [H2]3
Kc = [Fe2O3] [H2]3 / [Fe]2 [H2O]3
B)
D)
Kc = [Fe]2 [H2O]3 / [Fe2O3] [H2]3
Kc = [H2O] / [H2]
Consider the following equilibria:
SO2(g) + 1/2O2(g) ⇌ SO3(g)
K1
2SO3(g) ⇌ 2SO2(g) + O2(g)
K2
The values of the equilibrium constants K1 and K2 are related by:
A)
14.
K2 = (K1)2
B)
(K2)2= K1
C)
K2 = (K1)-2
D)
K2 = (K1)-1
D)
0.424
D)
2 and 3
For the following reaction Kc = 1.210-4 at 295.0 K.
NH4HS(s) ⇌ NH3(g) + H2S(g)
Calculate (in atm) the partial pressure of NH3 gas at equilibrium.
A)
15.
0.117
B)
0.265
C)
0.344
Consider the following reaction at equilibrium:
2SO2(g) + O2(g) ⇌ 2SO3(g)
Hrn = -198 kJ
Which of the following statements could be true?
1) Kp increases with decreasing temperature.
2) Kp increases with increasing temperature.
3) Kp increases with decreasing total pressure.
4) Kp increases with increasing total pressure.
A)
1 only
B)
1 and 4
C)
-2-
2 only