What is ${\mathrm{K}}_{\mathrm{b}}$ for the aqueous fluoride ion given that ${\mathrm{K}}_{\mathrm{w}}$ is $1.0\times {10}^{-14}$ and ${\mathrm{K}}_{\mathrm{a}}$ for $\mathrm{HF}$ is $6.8\times {10}^{-4}$ at $298 \mathrm{K}$?

Ammonia, ${\mathrm{NH}}_3$ , is a weak base. It has a ${\mathrm{pK}}_{\mathrm{b}}$ value of $4.75$.

Calculate the pH of a $1.00\times {10}^{-2} \mathrm{mol} {\mathrm{dm}}^{-3}$ aqueous solution of ammonia at $298 \mathrm{K}$.

Distinguish between the terms strong and weak acid and state the equations used to show the dissociation of acids ${\mathrm{HNO}}_3$ and $\mathrm{HCN}$ in aqueous solution.

Ammonia can be converted into nitric acid, ${\mathrm{HNO}}_3\left(\mathrm{aq}\right)$, and hydrocyanic acid, $\mathrm{HCN}\left(\mathrm{aq}\right)$. The ${\mathrm{pK}}_{\mathrm{a}}$ of hydrocyanic acid is $9.21$.

Deduce the expression for the ionization constant, ${\mathrm{K}}_{\mathrm{a}}$, of hydrocyanic acid and calculate its value from the ${\mathrm{pK}}_{\mathrm{a}}$ value given.

Ammonia can be converted into nitric acid, ${\mathrm{HNO}}_3\left(\mathrm{aq}\right)$, and hydrocyanic acid, $\mathrm{HCN}\left(\mathrm{aq}\right)$. The ${\mathrm{pK}}_{\mathrm{a}}$ of hydrocyanic acid is $9.21$.

Calculate the $\left[{\mathrm{H}}^{+}\right]$ and the $\mathrm{pH}$ of an aqueous solution of hydrocyanic acid of concentration $0.108 \mathrm{mol} {\mathrm{dm}}^{-3}$. State one assumption made in arriving at your answer.

$0.100 \mathrm{mol}$ of ammonia, ${\mathrm{NH}}_3$, was dissolved in water to make $1.00 {\mathrm{dm}}^3$ of solution. This solution has a hydroxide ion concentration of $1.28\times {10}^{-3} \mathrm{mol} {\mathrm{dm}}^{-3}$. Determine the $\mathrm{pH}$ of the solution.

$0.100 \mathrm{mol}$ of ammonia, ${\mathrm{NH}}_3$, was dissolved in water to make $1.00 {\mathrm{dm}}^3$ of solution. This solution has a hydroxide ion concentration of $1.28\times {10}^{-3} \mathrm{mol} {\mathrm{dm}}^{-3}$. Calculate the base dissociation constant, ${\mathrm{K}}_{\mathrm{b}}$, for ammonia.

Consider an acid–base indicator solution.

$$\begin{gathered} \mathrm{HIn}\left(\mathrm{aq}\right) \rightleftharpoons {\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{In}}^{-}\left(\mathrm{aq}\right) \\ \mathrm{colour} \mathrm{A} \mathrm{colour} \mathrm{B} \end{gathered}$$

What is the effect on this acid–base indicator when sodium hydroxide solution is added to it?