Quiz 3

Question 1

What is the effect on equilibrium when sodium formate is added to a solution of formic acid?
a. No change in the equilibrium.
b. Equilibrium shifts to the right.
c. More information if needed to answer the question.
d. Equilibrium shifts to the left.

Answer 1

d. Equilibrium shifts to the left.

Question 2

What is the conjugate base of sulfuric acid?
a. HSO4-
b. H3O+
c. OH-
d. SO42-
e. H3SO4+

Answer 2

a. HSO4-

Question 3

The OH- concentration in a 1.0x10^-3 M Ba(OH)2 solution is:
a. 0.50 x 10^-3 M
b. 1.0 x 10^-3
c. 2.0 x 10^-3
d. 1.0 x 10^-2
e. 0.020 M

Answer 3

c. 2.0 x 10^-3 M

Question 4

Consider the weak bases below and their Kb values:
C6H7O Kb= 1.3 x 10^-10
C2H5NH2 Kb= 5.6 x 10^-4
C5H5N Kb= 1.7 x 10^-9
Arrange the conjugate acids of these weak bases in order of increasing acid strength.

Answer 4

e. C2H5NH3+ < C5H5NH+ < C6H7OH

Question 5

Which of these species will act as a Lewis acid?
a. NH3
b. NH4+
c. H2O
d. BF3
e. F-

Answer 5

d. BF3

Question 6

Which of these species is a Lewis acid, but not a Bronsted acid?
a. HCN
b. CO32-
c. OH-
d. CI-
e. AI3+

Answer 6

e. AI3+

Question 7

What is the pH of a 0.050 M triethylamine, (C2H5)3N, solution?
Kb for triethylamine is 5.3 x 10^-4
a. 11.69
b. 8.68
c. 5.32
d. 2.31
e. <2.0

Answer 7

a. 11.69

Question 8

What is the [H3O+] for a solution at 25 degrees Celsius that has pOH = 5.640?

Answer 8

c. 4.37 x 10^-9 M

Question 9

Which of the following is the correct Kb expression for the reaction below?
B(aq) + H2O (l) <–> HB+(aq) + OH-(aq)

Answer 9

d. Kb = [HB+][OH-] / [B]