(a) For the preparation of cakes, baking powder is used. If at home your mother uses baking soda instead of baking powder, how will it affect the taste of the cake and why ?
(b) How is baking soda converted into baking powder?
(c) What makes the cake soft and spongy ?

Explanation

`underset("Baking Soda")(2NaHCO_(3)) overset("Heat")to underset(" Sodium Carbonate")(Na_(2)CO_(3)) + CO_(2) + H_(2)O`
For the preparation of cake if only sodium hydrogen carbonate (baking -soda) is used instead of backing powder then sodium carbonate is formed from it by the action of heat during baking . this will give a bitter taste to the cake. The advantage of using baking powder is that tartaric acid present in it can react with sodium carbonate formed and neutralise it to sodium tartrate salt and the cake has a pleasant taste.
(b) baking soda is a single compound, i.e, sodium hydrogen carbonate. it is converted into baking powder by mixing solid sodium hydrogen carbonate with solid edibte acid such as tartaric acid (or eitric acid).
(c) When baking powder mixes with water then sodium hydrogen carbonate reacts with tartaric acid to evolve `CO_(2)` gas
` NaHCO_(3) (aq) + H^(+) (aq) to Na^(+) (aq) + CO_(2)(g) + H_(2)O(I)`
The `CO_(2)` gas produced gets trapped in the wet dough and bubbles out slowly causing the cake (or bread) to rise and become soft and spongy.