Chapter 16

Which of the following is the stronger acid: \(\begin{array}{llll}\mathrm{CH}_{2} \mathrm{ClCOOH} & \text { or } \mathrm{CHCl}_{2} \mathrm{COOH} ? & \text { Explain your }\end{array}\) choice.

Consider the following compounds: Experimentally, phenol is found to be a stronger acid than methanol. Explain this difference in terms of the structures of the conjugate bases. (Hint: A more stable conjugate base favors ionization. Only one of the conjugate bases can be stabilized by resonance.

Define salt hydrolysis. Categorize salts according to how they affect the \(\mathrm{pH}\) of a solution.

Explain why small, highly charged metal ions are able to undergo hydrolysis.

\(\mathrm{Al}^{3+}\) is not a Bronsted acid, but \(\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}^{3+}\) is Explain.

Specify which of these salts will undergo hydrol\(\begin{array}{llll}\text { ysis: } \mathrm{KF}, & \mathrm{NaNO}_{3}, & \mathrm{NH}_{4} \mathrm{NO}_{2}, & \mathrm{MgSO}_{4}, & \mathrm{KCN},\end{array}\) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COONa}, \mathrm{RbI}, \mathrm{Na}_{2} \mathrm{CO}_{3}, \mathrm{CaCl}_{2}, \mathrm{HCOOK}\).

Prediet the \(\mathrm{pH}(>7,<7,\) or \(\approx 7)\) of the aqueous solutions containing the following salts: (a) \(\mathrm{KBr}\) (b) \(\mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}\) (c) \(\mathrm{BaCl}_{2}\) (d) \(\mathrm{Bi}\left(\mathrm{NO}_{3}\right)_{3}\).

A certain salt, MX (containing the \(\mathrm{M}^{+}\) and \(\mathrm{X}^{-}\) ions), is dissolved in water, and the \(\mathrm{pH}\) of the resulting solution is 7.0. Can you say anything about the strengths of the acid and the base from which the salt is derived?

In a certain experiment a student finds that the \(\mathrm{pHs}\) of \(0.10 M\) solutions of three potassium salts \(K X, K Y\) and \(\mathrm{KZ}\) are 7.0,9.0 , and 11.0 , respectively. Arrange the acids HX, HY, and HZ in order of increasing acid strength.

Calculate the \(\mathrm{pH}\) of a \(0.42 \mathrm{M} \mathrm{NH}_{4} \mathrm{Cl}\) solution.