(a) What is "baking powder"? How does it make the cake soft and spongy?
(b) In addition to sodium hydrogen carbonate, baking powders contain a substance X. Name the substance X. What is the role of substance X in the baking powder?
a) Baking powder is a mixture of sodium bicarbonate and cream of tartar, used instead of yeast in baking. It is mixed with the flour. When water is added to this flour to make the dough, baking powder undergoes a chemical reaction during which carbon dioxide gas is produced. Carbon dioxide gas gets trapped into the dough and bubbles out which causes the cake to rise and make it soft and spongy.
(b) Substance X is tartaric acid. It reacts with the sodium carbonate formed and neutralizes it otherwise the bread/dough will taste bitter.