Question

Salt A commonly used in bakery products on heating gets converted into another salt B which itself is used for the removal of hardness of water and a gas C is evolved. The gas C when passed through lime water, turns it milky. Identify A, B and C.

Answer 1

The salt A is sodium hydrogen carbonate (baking soda) and is commonly used in bakeries as a constituent of baking powder. Upon heating, it changes to sodium carbonate B and evolves carbon dioxide gas C.

`underset("'A'")(2"NaHCO"_3) overset("heat")(->)underset("'B'")("Na"_2"CO"_3) + underset("'C'")("CO"_2)`

Sodium carbonate removes hardness from water while CO₂ gas turns lime water milky.