234 ❯ STEP 4. Review the Knowledge You Need to Score High
- You are given equimolar solutions of each of the
following. Which has the lowest pH?
(A) NH 4 Cl
(B) NaCl
(C) K 3 PO 4
(D) Na 2 CO 3 - When sodium nitrite dissolves in water:
(A) The solution is acidic because of the hydrolysis
of the sodium ion.
(B) The solution is basic because of the hydrolysis
of the NO 2 - ion
(C) The solution is basic because of the hydrolysis
of the sodium ion.
(D) The solution is acidic because of the hydrolysis
of the NO 2 - ion.- Which of the following solutions has a pH nearest 7?
(A) 1 M H 2 C 2 O 4 (oxalic acid) and 1 M KHC 2 O 4
(potassium hydrogen oxalate)
(B) 1 M KNO 3 (potassium nitrate) and 1 M
HNO 3 (nitric acid)
(C) 1 M NH 3 (ammonium nitrate) and 1 M
NH 4 NO 3 (ammonium nitrate)
(D) 1 M CH 3 NH 2 (methylamine) and 1 M
HC 2 H 3 O 2 (acetic acid)- Determine the OH-(aq) concentration in a
1.0 M aniline (C 6 H 5 NH 2 ) solution. The Kb for
aniline is 4.0 × 10 -^10.
(A) 2.0 × 10 -^5 M
(B) 4.0 × 10 -^10 M
(C) 3.0 × 10 -^6 M
(D) 5.0 × 10 -^7 M - A student wishes to reduce the zinc ion con-
centration in a saturated zinc iodate solution to
1 × 10 -^6 M. How many moles of solid KIO 3 must
be added to 1.00 L of solution? [Ksp Zn(IO 3 ) 2 =
4 × 10 -^6 at 25°C.]
(A) 1 mole
(B) 0.5 mole
(C) 2 moles
(D) 4 moles
13. At constant temperature, a change in volume will
NOT affect the moles of substances present in
which of the following?
(A) H 2 (g) + I 2 (g) ^ 2 HI(g)
(B) CO(g) + Cl 2 (g) ^ COCl 2 (g)
(C) PCl 5 (g) ^ PCl 3 (g) + Cl 2 (g)
(D) N 2 (g) + 3 H 2 (g) ^ 2 NH 3 (g)
14. The equilibrium constant for the hydrolysis
of C 2 O 42 - is best represented by which of the
following?
(A) K = [OH-] [C 2 O 42 - ]/[HC 2 O 4 - ]
(B) K = [H 3 O+] [C 2 O 42 - ]/[HC 2 O 4 - ]
(C) K = [HC 2 O 4 - ] [OH-]/[C 2 O 42 - ]
(D) K = [C 2 O 42 - ]/[HC 2 O 4 - ] [OH-]
15. ZnS(s) + 2 H+(aq) ^ Zn^2 +(aq) + H 2 S(aq)
What is the equilibrium constant for the above
reaction? The successive acid dissociation con-
stants for H 2 S are 9.5 × 10 -^8 (Ka1) and 1 × 10 -^19
(Ka2). The Ksp, the solubility product constant,
for ZnS equals 1.6 × 10 -^24.
(A) 1.6 × 10 -^24 /9.5 × 10 -^8
(B) 1 × 10 -^79 /1.6 × 10 -^24
(C) 1.6 × 10 -^24 /9.5 × 10 -^27
(D) 9.5 × 10 -^8 /1.6 × 10 -^24
16. C(s) + H 2 O(g) ^ CO(g) + H 2 (g) endothermic
An equilibrium mixture of the reactants is placed
in a sealed container at 150°C. The amount of
the products may be increased by which of the
following changes?
(A) decreasing the volume of the container
(B) raising the temperature of the container and
increasing the volume of the container
(C) lowering the temperature of the container
(D) adding 1 mole of C(s) to the container