WAEC Chemistry 2025 Theory — Question 31

Model answer

Na: used in sodium vapour lamps, as coolant in nuclear reactors, as a reducing agent, in production of NaOH, Na2O2 and NaCN. Cl: used in manufacture of HCl, as a bleaching agent, as a germicide in water treatment, in manufacture of plastics, dyes and drugs. Ca: used in deoxidation in steel casting/copper alloys, formation of healthy teeth and bones. O: used as an antiseptic/disinfectant, as a raw material in the production of steel, in the oxy-ethyne flame for welding, as an oxidizer in rocket fuel, and in respiration/life support/sea diving.