Chapter 16

Compare the magnitudes of $\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right]$ and $\left[{\mathrm{OH}}^{-}\right]$ in aqueous solutions that are acidic, basic, and neutral.

Calculate the ${\mathrm{OH}}^{-}$ concentration in aqueous solution at ${25}^{\circ }\mathrm{C}$ with each of the following ${\mathrm{H}}_3{\mathrm{O}}^{+}$ concentrations: (a) $1.13\times {10}^{-4}\mathrm{M}$ (b) $4.55\times {10}^{-8}\mathrm{M}$ (c) $7.05\times {10}^{-11}\mathrm{M}$, (d) $3.13\times {10}^{-2}M$.

Calculate the ${\mathrm{H}}_3{\mathrm{O}}^{+}$ concentration in an aqueous solution at ${25}^{\circ }\mathrm{C}$ with each of the following ${\mathrm{OH}}^{-}$ concentrations: (a) $2.50\times {10}^{-2}M$ (b) $1.67\times {10}^{-5}M$ (c) $8.62\times {10}^{-3}\mathrm{M}$ (d) $1.75\times {10}^{-12}\mathrm{M}$.

Indicate which of the following species could, in theory, undergo autoionization: (a) ${\mathrm{NH}}_3$; (b) ${\mathrm{NH}}_4^{+};$ (c) ${\mathrm{OH}}^{-}$; (d) ${\mathrm{O}}^{2-}$; (e) $\mathrm{HF};$ (f) ${\mathrm{F}}^{-}$

Define $\mathrm{pH}$. Why do chemists normally choose to discuss the acidity of a solution in terms of $\mathrm{pH}$ rather than hydronium ion concentration $\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right]?$

The $\mathrm{pH}$ of a solution is 6.7 . From this statement alone, can you conclude that the solution is acidic? If not, what additional information would you need? Can the $\mathrm{pH}$ of a solution be zero or negative? If so, give examples to illustrate these values.

Define $\mathrm{pOH}$. Write the equation relating $\mathrm{pH}$ and $\mathrm{pOH}$.

Calculate the concentration of ${\mathrm{OH}}^{-}$ ions in a $1.4\times {10}^{-3}\mathrm{M}$ $\mathrm{HCl}$ solution.

Calculate the concentration of ${\mathrm{OH}}^{-}$ ions in a $1.4\times {10}^{-3}\mathrm{M}$ $\mathrm{HCl}$ solution.

Calculate the $\mathrm{pH}$ of each of the following solutions: (a) $2.8\times {10}^{-4}\mathrm{MBa}(\mathrm{OH}{)}_2$ (b) $5.2\times {10}^{-4}\mathrm{M}{\mathrm{HNO}}_3$