91Ó°ÊÓ

A fictional weak base, ZaH_ , reacts with water to yield a solution with a \(\mathrm{OH}^{-}\) ion concentration of \(2.68 \times 10^{-4}\) \(\mathrm{mol} / \mathrm{L}\) . The chemical equation for the reaction is \(\mathrm{ZaH}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(1) \rightleftharpoons \mathrm{ZaH}_{3}^{+}(\mathrm{aq})+\mathrm{OH}^{-}(\mathrm{aq})\) If \(\left[\mathrm{ZaH}_{2}\right]\) at equilibrium is 0.0997 \(\mathrm{mol} / \mathrm{L}\) , what is the value of \(K_{\mathrm{b}}\) for \(\mathrm{ZaH}_{2} ?\)

Select a strong acid, and explain how you would prepare a dilute solution of the acid. Select a weak acid, and explain how you would prepare a concentrated solution of the acid.

What is the relationship between the pOH and the OH- ion concentration of a solution?

Solution A has a pH of 2.0. Solution B has a pH of 5.0. Which solution is more acidic? Based on the H't ion concentrations in the two solutions, how many times more acidic?

If the concentration of \(\mathrm{H}^{+}\) ions in an aqueous solution decreases, what must happen to the concentration of \(\mathrm{OH}^{-}\) ions? Why?

Use Le Chátelier's principle to explain what happens to the equilibrium \(\mathrm{H}_{2} \mathrm{O}(1) \rightleftharpoons \mathrm{H}^{+}(\mathrm{aq})+\mathrm{OH}^{-(\mathrm{aq})}\) when a few drops of HCl are added to pure wate.

What is \(\left[\mathrm{OH}^{-}\right]\) in an aqueous solution at 298 \(\mathrm{K}\) in which \(\left[\mathrm{H}^{+}\right]=5.40 \times 10^{-3} \mathrm{M} ?\)

If 5.00 mL of 6.00\(M\) HCl is added to 95.00 mL of pure water, the final volume of the solution is 100.00 \(\mathrm{mL}\) . What is the pH of the solution?

Given two solutions, 0.10 \(\mathrm{M} \mathrm{HCl}\) and 0.10 \(\mathrm{M}\) HF, which solution has the greater concentration of \(\mathrm{H}^{+}\) ions? Calculate pH values for the two solutions, given that \(\left[\mathrm{H}^{+}\right]=7.9 \times 10^{-3} \mathrm{M}\) in the 0.10 \(\mathrm{M} \mathrm{HF}\)

Metal Cleaner Chromic acid is used as an industrial cleaner for metals. What is \(K_{\mathrm{a}}\) for the second ionization of chromic acid \(\left(\mathrm{H}_{2} \mathrm{CrO}_{4}\right)\) if a 0.040 \(\mathrm{M}\) solution of sodium hydrogen chromate has a pH of 3.946?