Question

Two of the most commonly used salts are sodium chloride (NaCI) and sodium bicarbonate (NaHCO₃). Find out which of these is used (i) as baking powder, (ii) as a preservative in pickles and in preserving meat and fish and also think of the respective reasons for doing so.

Answer 1

(i) Sodium bicarbonate (NaHCO₃) is used as baking powder.
When added to a batter, sodium bicarbonate reacts with the acidic components present in it and releases carbon dioxide. This causes expansion of the batter, which gives a characteristic texture to it.

(ii) Sodium chloride (NaCl) is used as a preservative in pickles. It is also used in preserving meat and fish.
Being a neutral substance, sodium chloride does not bring any change, either acidic or basic, when added to a food substance. In this way, the food substance can be preserved for a long period of time.