Chapter 15

Nicotine Addiction Nicotine is responsible for the addictive properties of tobacco. What is the \(\mathrm{pH}\) of a \(1.00 \times 10^{-3} \mathrm{M}\) solution of nicotine?

Explain why the \(K_{\mathrm{a}_{1}}\) of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is much greater than the \(K_{\mathrm{a}_{1}}\) of \(\mathrm{H}_{2} \mathrm{SeO}_{4}\).

Explain why the \(K_{a_{1}}\) of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is much greater than the \(K_{\mathrm{a}_{1}}\) of \(\mathrm{H}_{2} \mathrm{SO}_{3}\)

Predict which acid in the following pairs of acids is the stronger acid: (a) \(\mathrm{H}_{2} \mathrm{SO}_{3}\) or \(\mathrm{H}_{2} \mathrm{SeO}_{3} ;\) (b) \(\mathrm{H}_{2} \mathrm{SeO}_{4}\) or \(\mathrm{H}_{2} \mathrm{SeO}_{3}.\)

Trifluoroacetic acid, \(\mathrm{CF}_{3} \mathrm{COOH},\) is more than \(10^{4}\) times as strong as acetic acid, \(\mathrm{CH}_{3} \mathrm{COOH}\). Explain why.

Why is it unnecessary to publish tables of \(K_{b}\) values of the conjugate bases of weak acids whose \(K_{\mathrm{a}}\) values are known?

Which of the following salts produces an acidic solution in water: ammonium acetate, ammonium nitrate, or sodium formate?

Which of the following salts produces a basic solution in water: \(\mathrm{NaF}, \mathrm{KCl}, \mathrm{NH}_{4} \mathrm{Cl} ?\)

Neutralizing the Smell of Fish Trimethylamine, \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{N}\) \(K_{\mathrm{b}}=6.5 \times 10^{-5}\) at \(25^{\circ} \mathrm{C},\) is a contributor to the "fishy" odor of not-so-fresh seafood. Some people squeeze fresh lemon juice (which contains a high concentration of citric acid) on cooked fish to reduce the fishy odor. Why is this practice effective?

The \(K_{\mathrm{a}}\) of the conjugate acid of the artificial sweetener saccharin is \(2.1 \times 10^{-11} .\) What is the \(\mathrm{p} K_{\mathrm{b}}\) for saccharin?

The \(K_{2}\) value for oxalic acid (HOOCCOOH) is \(5.9 \times 10^{-2},\) and the \(K_{2,2}\) value is \(6.4 \times 10^{-5} .\) What are the values of \(K_{\mathrm{b}_{1}}\) and \(K_{\mathrm{b}_{2}}\) of the oxalate anion \(\left(^{-} \mathrm{OOCCOO}^{-}\right) ?\)

Dental Health Sodium fluoride is added to many municipal water supplies to reduce tooth decay. Calculate the pH of a \(0.00339 M\) solution of \(\mathrm{NaF}\) at \(25^{\circ} \mathrm{C}\)

Calculate the pH of a \(1.25 \times 10^{-2} M\) solution of the decongestant ephedrine hydrochloride if the \(\mathrm{p} K_{\mathrm{b}}\) of ephedrine (its conjugate base) is 3.86.

Consider the following compounds: \(\mathrm{CH}_{3} \mathrm{NH}_{2}\) \(\mathrm{CH}_{3} \mathrm{COOH}, \mathrm{Ca}(\mathrm{OH})_{2},\) and \(\mathrm{HClO}_{4}.\) Identify the Arrhenius acid(s). b. Identify the Arrhenius base(s). c. Identify the Brensted-Lowry acid(s). d. Identify the Brensted-Lowry base(s).

Are all Arrhenius acids also Bronsted-Lowry acids? Are all Bronsted-Lowry acids also Arrhenius acids? If yes, explain why. If not, give a specific example to demonstrate the difference.

Are all Arrhenius bases also Brensted-Lowry bases? Are all Bronsted-Lowry bases also Arrhenius bases? If yes, explain why. If not, give a specific example to demonstrate the difference.

Describe the intermolecular forces and changes in bonding that lead to the formation of a basic solution when methylamine (CH \(_{3} \mathrm{NH}_{2}\) ) dissolves in water.

The \(K_{\mathrm{a}_{1}}\) of phosphorous acid, \(\mathrm{H}_{3} \mathrm{PO}_{3},\) is nearly the same as the \(K_{\mathrm{a}_{1}}\) of phosphoric acid, \(\mathrm{H}_{3} \mathrm{PO}_{4}.\) a. Draw the Lewis structure of phosphorous acid. b. Identify the ionizable hydrogen atoms in the structure. c. Explain why the \(K_{\mathrm{a}_{1}}\) values of phosphoric and phosphorous acid are similar.

Sulfuric acid reacts with nitric acid as follows: \(\mathrm{HNO}_{3}(a q)+2 \mathrm{H}_{2} \mathrm{SO}_{4}(a q) \rightarrow \mathrm{NO}_{2}^{+}(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q)+2 \mathrm{HSO}_{4}^{-}(a q)\) a. Is the reaction a redox process? b. Identify the acid, base, conjugate acid, and conjugate base in the reaction. (Hint: Draw the Lewis structures for each.)

Thiosulfuric acid, \(\mathrm{H}_{2} \mathrm{S}_{2} \mathrm{O}_{3},\) can be prepared by the reaction of \(\mathrm{H}_{2} \mathrm{S}\) with \(\mathrm{HSO}_{3} \mathrm{Cl}\) : $$\mathrm{HSO}_{3} \mathrm{Cl}(\ell)+\mathrm{H}_{2} \mathrm{S}(g) \rightarrow \mathrm{HCl}(g)+\mathrm{H}_{2} \mathrm{S}_{2} \mathrm{O}_{3}(\ell)$$ a. Draw a Lewis structure for \(\mathrm{H}_{2} \mathrm{S}_{2} \mathrm{O}_{3},\) given that it is isostructural with \(\mathrm{H}_{2} \mathrm{SO}_{4}\) b. Do you expect \(H_{2} S_{2} O_{3}\) to be a stronger or weaker acid than \(\mathrm{H}_{2} \mathrm{SO}_{4} ?\) Explain your answer.