Exercises 789*058.Because Kbis larger for triethylamine(C 2 H 5 ) 3 N(aq)H 2 O() 34 (C 2 H 5 ) 3 NHOH
Kb5.2 10 ^4than for trimethylamine(CH 3 ) 3 N(aq)H 2 O() 34 (CH 3 ) 3 NHOH
Kb7.4 10 ^5an aqueous solution of triethylamine should have a larger
concentration of OHion than an aqueous solution of
trimethylamine of the same concentration. Confirm this
statement by calculating the [OH] for 0.012 Msolutions
of both weak bases.
*059.The equilibrium constant of the following reaction is
1.35 10 ^15.2D 2 O 34 D 3 OODD is deuterium,^2 H. Calculate the pD of pure deuterium
oxide (heavy water). What is the relationship between
[D 3 O] and [OD] in pure D 2 O? Is pure D 2 O acidic,
basic, or neutral?Polyprotic Acids
*060.Calculate the concentrations of the various species in a
0.100 MH 3 AsO 4 solution. Compare the concentrations
with those of the analogous species in 0.100 MH 3 PO 4
solution (Example 18-16 and Table 18-7).
*061.Citric acid, the acid in lemons and other citrus fruits, has
the structurewhich we may abbreviate as C 3 H 5 O(COOH) 3 or H 3 A. It
is a triprotic acid. Write the chemical equations for the
three stages in the ionization of citric acid with the appro-
priate Kaexpressions.HO COOHCH 2 COOHCH 2 COOHC*062.Calculate the concentrations of H 3 O, OH, HSeO 4 ,
and SeO 42 in 0.12 MH 2 SeO 4 , selenic acid, solution.
*063.Some kidney stones are crystalline deposits of calcium
oxalate, a salt of oxalic acid, (COOH) 2. Calculate the
concentrations of H 3 O, OH, COOCOOH, and
(COO) 2 in 0.12 M(COOH) 2. Compare the concentra-
tions with those obtained in Exercise 62. How can you
explain the difference between the concentrations of
HSeO 4 and COOCOOH? between SeO 42 and
(COO) 2?
*064.Rust stains can be removed from painted surfaces with a
solution of oxalic acid, (COOH) 2. Calculate the pH of a
0.050 Moxalic acid solution.
*065.Calculate the pH and pOH of a carbonated soft drink
that is 0.0032 Mcarbonic acid solution. Assume that there
are no other acidic or basic components.Hydrolysis
*066.Define and illustrate the following terms clearly and con-
cisely: (a) solvolysis; (b) hydrolysis.
*067.Predict which base of each pair is the stronger base.
Briefly explain how you arrived at your answer. (a) NO 2
or NO 3 ; (b) BrO 3 or IO 3 ; (c) HSO 3 or HSO 4 .
(Hint: You may wish to review Chapter 10.)
*068.Predict which base of each pair is the stronger base.
Briefly explain how you arrived at your answer. (a) PH 3
or NH 3 ; (b) Bror F; (c) ClO 3 or ClO 2 . (Hint: You
may wish to review Chapter 10.)
*069.Some anions, when dissolved, undergo no significant
reaction with water molecules. What is the relative base
strength of such an anion compared with water? What
effect will dissolution of such anions have on the pH of
the solution?
*070.Some cations in aqueous solution undergo no significant
reactions with water molecules. What is the relative acid
strength of such a cation compared with water? What
effect will dissolution of such cations have on the pH of
the solution?
*071.How can salts be classified conveniently into four classes?
For each class, write the name and formula of a salt that
fits into that category. Use examples other than those used
in illustrations in this chapter.