Name: 
 

Chemistry 12 - Chapter 7 Quiz



True/False
Indicate whether the sentence or statement is true or false.
 

1. 

Chemical equilibrium means that all chemical reactions have stopped.
 

2. 

Equilibrium can only occur in a closed system.
 

3. 

A catalyst shifts the position of equilibrium toward the products.
 

4. 

Reactions with a lower activation energy achieve equilibrium faster.
 

5. 

According to Le Châtelier’s principle, a reaction at equilibrium whose c12-ch7_files/i0060000.jpgH is c12-ch7_files/i0060001.jpg512 kJ will shift to the right if heated.
 

6. 

If the trial ion product is less than Ksp, a precipitate will form.
 

7. 

If c12-ch7_files/i0080000.jpgH is negative and c12-ch7_files/i0080001.jpgS is negative, the reaction will be spontaneous only at high temperatures.
 

8. 

A reaction whose c12-ch7_files/i0090000.jpgG is zero is at equilibrium.
 

9. 

All chemical reactions are, in principle, reversible.
 

10. 

If K=1, the concentrations of the reactants and products are approximately equal.
 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

11. 

In a dynamic equilibrium
a.
macroscopic properties are constant.
b.
reactants are converted to products.
c.
products are converted to reactants.
d.
rates of forward and reverse reactions are equal.
e.
all of the above.
 

12. 

Which of the following affect the value of the
equilibrium constant?
a.
temperature
b.
small changes in concentration
c.
the density of a slightly soluble salt
d.
small changes in the pressure of a gas
e.
(a) and (b)
 

13. 

Which is the correct form of the equilibrium law expression for the following reaction?
2 SO3(g) c12-ch7_files/i0150000.jpg 2 SO2(g) + O2(g)
a.
K  c12-ch7_files/i0150001.jpg
b.
K c12-ch7_files/i0150002.jpg
c.
K c12-ch7_files/i0150003.jpg
d.
K =  [SO2(g)][O2(g)]2
e.
none of the above
 

14. 

If the equilibrium constant, K, for the conversion of isobutane to n-butane is 2.5, what is the value of the equilibrium constant for the reverse reaction?
a.
2.5
b.
0.4
c.
6.25
d.
1.3
e.
1.0
 

15. 

What is the Ksp of PbCl2 if, in a saturated solution of this salt, [Cl-(aq)] = 0.032 mol/L ?
a.
5.1 c12-ch7_files/i0170000.jpg 10-4
b.
4.8 c12-ch7_files/i0170001.jpg 10-3
c.
3.9 c12-ch7_files/i0170002.jpg 10-5
d.
1.6 c12-ch7_files/i0170003.jpg 10-5
e.
6.2 c12-ch7_files/i0170004.jpg 10-2
 

16. 

Given the equilibrium
AgBr(s)  c12-ch7_files/i0180000.jpg  Ag+(aq) + Br-(aq)      Ksp = 3.3  c12-ch7_files/i0180001.jpg  10-13
      If [Br-(aq)] = 0.50 mol/L, what is [Ag+(aq)]?
a.
6.6 c12-ch7_files/i0180002.jpg 10-13
b.
1.7 c12-ch7_files/i0180003.jpg 10-13
c.
1.5 c12-ch7_files/i0180004.jpg 1012
d.
3.3 c12-ch7_files/i0180005.jpg 10-13
e.
7.5 c12-ch7_files/i0180006.jpg 1012
 

17. 

What will happen to [Pb2+(aq)] in the following equilibrium if NaCl(s) is added to the container?
PbCl2(s)  c12-ch7_files/i0190000.jpg  Pb2+(aq) + 2Clc12-ch7_files/i0190001.jpg(aq)
a.
It will decrease.
b.
It will increase.
c.
It will remain the same.
d.
It will increase at first, then decrease.
e.
The answer cannot be determined.
 

18. 

Predict the effect on the following equilibrium if the volume of the flask is decreased.
Cl2(g) + 3 F2(g)  c12-ch7_files/i0200000.jpg  2 ClF3(g) + heat
a.
The reaction shifts right.
b.
The reaction shifts left.
c.
There is no change in equilibrium position.
d.
The reaction first shifts right, then left.
e.
none of the above
 

19. 

For which of the following is the entropy change negative?
a.
a skier skiing down a slope
b.
paper burning
c.
H2O(g) c12-ch7_files/i0210000.jpg H2O(l)
d.
NaCl(s) c12-ch7_files/i0210001.jpg NaCl(aq)
e.
none of the above
 

20. 

In which of the following cases does the tendency to maximum entropy favour the forward reaction?
a.
Br2(l)  c12-ch7_files/i0220000.jpg  Br2(lg
b.
N2(g) + 3 H2(g)  c12-ch7_files/i0220001.jpg  2 NH3(g)
c.
Li+(aq) + Cl-(aq)  c12-ch7_files/i0220002.jpg  LiCl(s)
d.
6 C(s) + 3 H2(g)  c12-ch7_files/i0220003.jpg  C6H6(l)
e.
CaO(s) + CO2(g) c12-ch7_files/i0220004.jpg CaCO3(s)
 



 
Check Your Work     Reset Help