What is "baking powder"? How does it make the cake soft and spongy? (b) In addition to sodium hydrogencarbonate, baking powder contain a substance X. Name the substance. What is the role of substance X in the baking powder?

(a) Baking powder is a mixture of baking soda and tartaric acid when mixed with water the sodium hydrogen carbonate reacts with tartaric acid carbon dioxide gas is liberates and trapped in wet dough and bubbles out slowly making the cake soft and spongy.

(b) Substance X is tartaric acid and it reacts with sodium carbonate formed and neutralise it otherwise cakes and breads will taste bitter.