Aqueous calcium hydroxide reacts with dilute ethanoic acid. $2\text{CH}_3\text{COOH} + \text{Ca(OH)}_2 \rightarrow (\text{CH}_3\text{COO})_2\text{Ca} + 2\text{H}_2\text{O}$ A learner reacts $25.0\,\text{cm}^3$ of $0.0100\,\text{mol dm}^{-3}$ aqueous calcium hydroxide with dilute ethanoic acid, using thymolphthalein as the indicator. Exactly $12.5\,\text{cm}^3$ of dilute ethanoic acid reacts with the $0.0100\,\text{mol dm}^{-3}$ aqueous calcium hydroxide. Calculate the concentration, in $\text{mol dm}^{-3}$, of the dilute ethanoic acid.
State the colour that thymolphthalein shows in aqueous calcium hydroxide.
Define the term weak in the phrase weak acid.
Write the formula of the ion present in aqueous solutions of acids.
Dilute ethanoic acid reacts with sodium carbonate. $2\text{CH}_3\text{COOH} + \text{Na}_2\text{CO}_3 \rightarrow 2\text{CH}_3\text{COONa} + \text{H}_2\text{O} + \text{CO}_2$ Calculate the volume, measured at r.t.p., of carbon dioxide produced, in $\text{cm}^3$, when $3.18\,\text{g}$ of sodium carbonate reacts with excess dilute ethanoic acid.
State one source of sulfur dioxide in the air.
Describe one method of reducing the amount of sulfur dioxide getting into the air.
In the Contact process, sulfur dioxide reacts with oxygen. Complete the symbol equation for this reaction. $2\text{SO}_2 + \text{O}_2 \rightleftharpoons \ldots\ldots\ldots$