Download 4. Which of the following describes how a Keq value is related to the

Chemistry 12
Quiz II - 1
Unit II.1 – II.6
Entropy, Le Chatelier, Keq
1.
Which of the following is correct for all systems at equilibrium?
I
The temperature is constant.
II
[Reactants] = [Products]
III Forward and reverse reactions are occurring.
IV The forward and reverse reaction rates are equal.
A. I and II only
B. I, III and IV only
C. II, III and IV only
D. III and IV only
Use the following equilibrium system to answer the next TWO questions.
4NH3(g) + 3O2(g) ⇌ 2N2(g) 6H2O(l) ;ΔH = -1530 kJ
2.
Which of the following would cause the amount of NH3 at equilibrium to increase?
A. an increase in [O2]
B. a decrease in volume
C. a decrease in temperature
D. an increase in temperature
3.
What happens when O2 is added to the above system?
Equilibrium
[N2]
A.
no shift
unchanged
B.
shifts right
decreases
C.
shifts right
increases
D.
shifts left
increases
4.
Which of the following describes how a Keq value is related to the relative
concentrations of reactants and products?
Keq value
Relative Concentration
I.
large
[products]>[reactants]
II.
large
[reactants]>[products]
III.
small
[products]>[reactants]
IV.
small
[reactants]>[products]
A. I only
B. IV only
C. I and IV only
D. II and III only
5.
Consider the potential energy diagram below.
If the PE diagram represents a reversible reaction that reaches equilibrium, which of the
following must be true for the forward reaction?
A. Enthalpy change favours products and entropy is increasing.
B. Enthalpy change favours reactants and entropy is increasing.
C. Enthalpy change favours products and entropy is decreasing.
D. Enthalpy change favours reactants and entropy is decreasing.
6.
Consider the following:
Energy + NH4SH(s) ⇌ NH3(g) + H2S(g)
Which of the following describes how enthalpy and entropy change in the forward direction?
Enthalpy
Entropy
A.
increasing
increasing
B.
increasing
decreasing
C.
decreasing
decreasing
D.
decreasing
increasing