(a) State the chemical property in each case on which the following uses of baking soda are based upon: (i) as an anti-acids (ii) as a constituent in…

(a) (i) Baking soda is used as an antacid because it is a mild noncorrosive basic salt hence neutralises excess acid. (ii) Baking soda liberates carbon dioxide \(\displaystyle \left(\mathrm{CO}_{2}\right)\) gas on reaction with mild edible acid. (iii)In fire extinguishers, it acts as a base to react with acid to produce carbon dioxide \(\displaystyle \left(\mathrm{CO}_{2}\right)\) gas to extinguish fire.

(i) \(\displaystyle \mathrm{Zn}+2 \mathrm{HCl} \longrightarrow \mathrm{ZnCl}_{2}+\mathrm{H}_{2}\) Metal Acid Zinc chloride

(ii) \(\displaystyle 2 \mathrm{NaOH}+\mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+2 \mathrm{H}_{2} \mathrm{O}\) Base Acid Sodium Sulphate

(iii) \(\displaystyle \mathrm{Na}_{2} \mathrm{CO}_{3}+2 \mathrm{HCl} \longrightarrow 2 \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2}\) Salt Acid Sodium chloride (Give marks if written with carbonate ion)