Hydrazine, ${\mathrm{N}}_2{\mathrm{H}}_4$, is a weak base. Write a chemical equation to show the equilibrium reaction of hydrazine with water.

The $\mathrm{pH}$ of a solution depends on the hydrogen ion (hydroxonium ion) concentration. Which concentration of ethanoic acid in Table $8.10$ has the highest concentration of hydrogen ions in solution?

Which acid or alkali in Table $8.10$ has the highest concentration of hydroxide ions?

Both hydrochloric acid and ethanoic acid react with magnesium. The rate of reaction of $1.0 \mathrm{mol} {\mathrm{dm}}^{-3}$ hydrochloric acid with magnesium is much faster than the rate of reaction of $1.0 \mathrm{mol} {\mathrm{dm}}^{-3}$ ethanoic acid. Explain why.

Use Table $8.11$ to identify: those indicators which could be used for a strong acid-strong base titration like the one in Figure $8.18$.

Use Table $8.11$to identify: the indicators that could not be used for the strong acid-strong base titration.

Suggest a suitable indicator to find the end-points of the reactions between: $0.0500 \mathrm{mol} {\mathrm{dm}}^{-3}$ nitric acid and $0.0500 \mathrm{mol} {\mathrm{dm}}^{-3}$ aqueous ammonia.