Question

What makes cakes and pastries to be light and fluffy?

Answer 1

Baking soda releases carbon dioxide $(C{{O}_{2}})$ when react with an acid. Baking powder is the mixture of baking soda and tartaric acid. The wheat dough traps the released carbon dioxide$(C{{O}_{2}})$ to make large pores in it.

Complete answer:
It is the baking soda which makes cakes and pastries to be light and fluffy. The chemical name and formula of baking soda is sodium bicarbonate and $NaHC{{O}_{3}}$. Baking soda is basic in nature and thus bitter in taste. Hence, a small amount of acid, usually a weak acid such as tartaric acid, is added in order to remove its bitterness and also activate it for releasing $C{{O}_{2}}$. This is illustrated by the following examples:
$2NaHC{{O}_{3}}+HOOC{{(CHOH)}_{2}}COOH\to {{}^{+}}N{{a}^{-}}OOC{{(CHOH)}_{2}}CO{{O}^{-}}N{{a}^{+}}+2{{H}_{2}}O+2C{{O}_{2}}$
In the above reaction, sodium bicarbonate reacts with tartaric acid and generates sodium tartrate, water and carbon dioxide. This released carbon dioxide is trapped by wheat dough (made by adding water into wheat flour) and thus makes pores in dough which is responsible for making cakes and pastries to be light and fluffy. That’s why baking powder is added in wheat dough because it is a combination of baking soda and tartaric acid.
Therefore, we can say that baking soda makes cakes and pastries to be light and fluffy.

Note:
It is important to note that baking soda is responsible for making cakes and pastries to be light and fluffy. The chemical name and formula of baking soda is sodium bicarbonate and $NaHC{{O}_{3}}$. Baking soda reacts with tartaric acid and generates sodium tartrate, water and carbon dioxide.