Chapter 17 Equilibrium
1. The forward and reverse reactions take place at the same rate
at equilibrium.
a. true
b. false
2. lf K is very large the system is mostly
a. Products
b. Reactants
3. lf K is very small the system is mostly
a. Products
b. Reactants
4. What is the solubility product constant expression (Kgp)
for the reaction:
Ag2 S(s)<— -— >2Ag+ + S-2
+
a. [Ag ][S-2 ]/[AgS]
c. [Ag+ ] [S-2}
b. [Ag2 S]/ [Ag+ ]2 [S-2 ]
d. [Ag,S]
5. What is the equilibrium expression for the following
equation? (all are gases)
A + 2B ÅÆ 3C + D
a. [C} 3 [D]/[A] {B]2
C. [3C][D]/[A][2B]
2
3
b. [A][B] / {C} [D]
d. [A][2B]/[3C][D]
6. An equilibrium reaction may be forced to completion by
a. adding a catalyst
b. increasing the pressure
c. increasing the temperature
d. removing the products from the reaction mixture as they
are formed
e. decreasing the reactant concentration
7. Given the reaction at equilibrium
N + 3H2(g) Å Æ 2NH3(g) + heat
Which change would shift the equilibrium to the products?
a. increase the temperature
b. increase the pressure
c. decrease the [N2 ]
d. decrease the [H2}
8. Given the reaction at equilibrium:
A(g) + B(g) Å ÆC(g) + D(g) + heat
As additional A is added to the system at constant
temperature, the concentration of B
a. decreases
b. increases
c. remains the same
H. Cannon, C. Clapper and T. Guillot
Klein High School
Equilibrium
The graph below shows the reaction rate of the same reaction with and without a catalyst.
Use it to help you answer the following questions.
9. Label each curve as with catalyst or without catalyst.
10. What does the graph show about the effect of a catalyst on the rate of a reaction?
11. In a chemical equation, how do you show that catalysts are not consumed or
chemically altered during a reaction?
12. A(n) _______ is a substance that interferes with the action of a catalyst.
13. What happens in reversible reactions?
14. Is the following statement true or false? Chemical equilibrium is a state in which
the forward and reverse reactions take place at different rates.
15. The equilibrium constant (Keq) is the ration of _____ concentrations to ______ at
equilibrium with each concentration raised to a power equal to the number of
_____ of that substance in the balanced chemical equation.
16. A value of Keq greater than 1 means that the _____ are favored over _____. A
value of Keq less than 1 means that _____ are favored over _____.
17-2
HC/CC/TG KHS
Equilibrium
Indicate the direction of the reaction for each of the following
changes: (both are gases)
N204 Å Æ 2NO2
19. NO2 is removed.
a. forward
b. reverse
20. N2 04 is added.
a. forward
b. reverse
21. N2 04 is removed.
a. forward
b. reverse
22. NO2 is added.
a. forward
b. reverse
23. When the volume of an equilibrium system is increased, the
reaction takes place in the direction that ____ the total
number of moles of gas.
a. decreases
b. increases
24. A(n) ____ in pressure shifts the position in such a way as
to decrease the number of moles of gas.
a. decrease
b. increase
Predict the direction of the shift if the pressure on the system is decreased by expansion.
25. Ni(s) + 4CO(s) Å ÆNi(CO)4(g)
26. ClF5(g) + ClF3(g) + F2(g)
27. HBr(g) Å Æ ½ H2(g) + l/2 Br2(g)
Predict the direction of the shift if the pressure is increased by compression,
28. H2O) + C (s) Å Æ CO(g) + H2(g)
29. SbCl5 + SbCl3 + Cl2(g)
20. CO(g) + H2O(g)
+ CO2(g)
+ H2(g)
17-3
HC/CC/TG KHS
Equilibrium
SO3(g) + heat Å Æ SO2(g) + ½ 02(g)
Predict whether the reverse or forward reaction will occur when the equilibrium is disturbed by:
1. Adding oxygen
2. Compressing the system at constant temperature
3. Adding argon gas
4. Decreasing the temperature
5. Removing sulfur dioxide
4NH3(g) + 302 Å Æ 2N2 + 6H2 O(l) + heat
How will the amount of ammonia at equilibrium be affected by:
6. Removing oxygen
7. Adding nitrogen
8. Adding water
9. Expanding the container at constant temperature
10. Increasing the temperature
Chapter 17
17-4
HC/CC/TG KHS