(a) Define an acid and a base. Give two examples of each.
(b) Give the names and formulae of two strong bases and two weak bases.
(c) What type of ions are formed:
(i) when an acid is dissolved in water?
(ii) when a base (or alkali) is dissolved in water?
(d) Write the neutralisation reaction between acids and bases in terms of the ions involved.
(e) Write any two important uses of bases.
(a) Acids are those chemical substances that have a sour taste. Example: Acetic acid and citric acid.
Base is a chemical substance that has a bitter taste. Example: Caustic soda and washing soda.
(b) Strong bases – Sodium hydroxide (NaOH), potassium hydroxide (KOH).
Weak bases – Calcium hydroxide $$(Ca(OH_2))$$, ammonium hydroxide $$(NH_4OH)$$.
(c)
(i) When an acid is dissolved in water Hydrogen ions are found.
(ii) When a base (or alkali) is dissolved in wate Hydroxide ions are found.
(d) Neutralisation reaction between acids and bases:
$$\underset{Hydrogen\ ions \ (From \ acid)}{H^+ (aq)}+ \underset{Hydroxide\ ions \ (from \ bases)}{OH^- (aq)} \xrightarrow[Reaction]{Neutralisation} \underset{Water}{H_2O(l)}$$
(e) Two important uses of bases are:
(i) Sodium hydroxide is used in the manufacture of soap, paper and rayon.
(ii) Calcium hydroxide is used in the manufacture of bleaching powder.