Baking Powder – It is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate, and a weak acid.

These baking acids are tartrate, phosphate, and sodium aluminium sulfate used alone or in combination.

It contains sodium bicarbonate. Hence, Option 4 is not correct.

It is used to increase the volume and lighten the texture of baked goods.

It works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture.

Source: Lucent