6 . Identify the conjugate acids and bases in the following equation:
NH 3 + H 2 O NH 4 + + OH−
7 . Identify each of the following as an Arrhenius acid or base, Brønsted-Lowry acid or base,
or Lewis acid or base:
(A) NaOH, in NaOH → Na+ + OH−
(B) HCl, in HCl → H+ + Cl−
(C) NH 3 , in NH 3 + H+ → NH 4 +
(D) NH 4 +, in NH 4 + → NH 3 + H+
(E) (CH 3 ) 3 N:, in (CH 3 ) 3 N: + BF 3 → (CH 3 ) 3 N:BF 3
8 . At equilibrium, a certain acid, HA, in solution yields [HA] = 0.94 M and [A−] = 0.060 M.
(A) Calculate Ka.
(B) Is this acid stronger or weaker than sulfurous acid (Ka = 1.7 × 10−2)?
(C) Calculate Kb.
(D) Calculate pH.
9 . For each of the following choices, choose that which describes the weaker acid:
(A) Ka = X, Ka = 3X
(B) [H+] = X, [H+] = 3X
(C) pH = X, pH = 3X
10 . For a certain acid, HA, Kb(A−) = 2.22 × 10−11. Calculate the pH of a 0.5 M solution of HA.
11 . Which of the following sets of materials would make the best buffer solution?