Question

For making cake, baking powder is taken. If you use baking soda instead, how will it affect the taste of cake and why? How can baking soda be converted into baking powder?

Answer 1

Hint: There is a difference in the chemical composition of baking powder and baking soda which is responsible for the difference in the taste that they impart to the cake. So let us try to understand their chemical composition.

Complete answer:
Baking powder contains a mixture of a weak base like a carbonate or bicarbonate along with a weak acid such as tartaric acid. Now we should also know that acids are sour to taste whereas bases are bitter. When baking powder is used as an ingredient to make cake, the acid and base react with each other and one of the products formed is carbon dioxide. This gas tries to expand within the cake batter and it leads to fluffiness of the cake. As the sour tasting acid is reacting with the bitter tasting base the resultant taste imparted to the cake is neither sour or bitter. In other words, the flavours are balanced. The neutralisation reaction can be represented with a balanced chemical equation as

$\mathop {{C_4}{H_6}{O_6}}\limits_{tartaric\;acid} + 2NaHC{O_3} \to \mathop {N{a_2}{C_4}{H_4}{O_6}}\limits_{sodium\;tartarate} + 2{H_2}O + 2C{O_2}$

If we use baking soda, its chemical composition is just sodium bicarbonate which is a mild base. Under the action of heat it decomposes to form sodium carbonate which is also a mild base. So it will make the taste of cake bitter though the cake will be fluffy due to the evolution of carbon dioxide. The chemical reaction which occurs will be

$2NaHC{O_3} \to N{a_2}C{O_3} + {H_2}O + C{O_2}$

Moving on to the second part of the question, conversion of baking soda to baking powder. So now we know the difference in the composition of baking soda and baking powder. So all that we need to do in order to convert baking soda into baking powder is add a weak acid like tartaric acid.

Note: Baking powder is called a leavening agent as it is used to rise the cake batter and make it fluffy. The pH of baking soda is high which may help delay fatigue, allowing us to exercise for a longer period of time.