South Carolina State University
Department of Biological and Physical Sciences
General Chemistry II, C 152-Hamidi; Homework Chapter 17 Name: …………….
_
___ 1. Which of the statements concerning equilibrium is false?
a
.
A
system that is disturbed from an equilibrium condition responds in a manner to restore
e
quilibrium.
b
.
E
quilibrium in molecular systems is dynamic, with two opposing processes balancing one
a
nother.
c
.
T
he value of the equilibrium constant for a given reaction mixture is the same regardless of
t
he direction from which equilibrium was attained.
d
.
A
system moves spontaneously toward a state of equilibrium.
e
.
T
he equilibrium constant usually is independent of temperature.
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___ 2. Consider the gas phase system below at a high temperature. The form of the expression for the equilibrium
constant, Kc, __________. 4NH3 + 5O2 4NO + 6H2O
a. cannot be determined without rate data
b. Kc =
c. Kc =
d. Kc =
e. Kc =
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___ 3. Nitrogen oxide and bromine combine to form nitrosyl bromide, NOBr.
2NO(g) + Br2(g) 2NOBr(g)
In a 5.0 liter reactor at equilibrium at a constant temperature, it was determined there was 0.45 mol NO, 0.17 mol
Br and 1.32 mol NOBr. What is the value of Kc at this temperature?
a. 0.0116 b. 86.2 c. 253 d. 0.00395 e.22.7
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___ 4. If the equilibrium constant at a certain temperature is 2.1 × 1013 for the following reaction,
4HCl(g) + O2(g) 2Cl2(g) + 2H2O(g)
calculate the value of the equilibrium constant at the same temperature for
Cl2(g) + H2O(g) HCl(g) + O2(g) .
a. 2.2 × 10-7 b. 3.8 × 103 c. 5.3 × 1012 d. 4.7 × 10-4 e. 1.2 × 10-14
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___ 5. The equilibrium constant, Kc, for the following gas phase reaction is 0.50 at 600°C. A mixture of HCHO, H2, and
CO is introduced into a flask at 600°C. After a short time, analysis of a small amount of the reaction mixture
shows the concentrations to be [HCHO] = 1.5 M, [H2] = 1.2 M, and [CO] = 1.0 M. Which of the following
statements about this reaction mixture is true? HCHO H2 + CO
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___ 6. Nitrosyl chloride, NOCl, dissociates on heating as shown below. When a 1.50-gram sample of pure NOCl is
heated at 350°C in a volume of 1.00 liter, the percent dissociation is found to be 57.2%. Calculate the equilibrium
concentration of NOCl. NOCl(g) NO(g) + Cl2(g)
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___ 7. The equilibrium constant for the following gas phase reaction is 4.0 at a certain temperature. A reaction is carried
out at this temperature starting with 2.0 mol/L of CO and 2.0 mol/L of H2O. What will be the equilibrium
concentration of H2? CO + H2O CO2 + H2
