1) Baking powder is typically composed of three main constituents:
- Baking soda (sodium bicarbonate): This is the primary ingredient responsible for the leavening action in baking powder. Baking soda is an alkaline compound that releases carbon dioxide gas when it reacts with an acidic ingredient or when heated.
- Acidic salts: Baking powder usually contains one or more acidic salts, such as cream of tartar (potassium bitartrate), sodium aluminum sulfate, or monocalcium phosphate. These acids react with baking soda to produce carbon dioxide gas.
- Starch: Starch is often added to baking powder to prevent the reaction between the acidic salts and baking soda from occurring prematurely. It helps to keep the ingredients dry and stable.
2) When baking powder is added to cake or bread batter, it causes the mixture to rise or swell due to the production of carbon dioxide gas. This gas forms as a result of the chemical reaction between the acidic salts in baking powder and the alkaline baking soda.
The chemical equation representing this reaction is:
Baking soda (sodium bicarbonate) + Acidic salt → Carbon dioxide gas + Water + Salt
For example, if cream of tartar is the acidic salt used in the baking powder, the equation would be:
Sodium bicarbonate + Potassium bitartrate → Carbon dioxide gas + Water + Potassium sodium tartrate
The carbon dioxide gas gets trapped within the batter, creating bubbles, which cause the mixture to rise and give the cake or bread a light and fluffy texture.
1)Give the constituents of baking powder.
2)Why does cake or bread swell on adding baking powder?Write the chemical equation
1 answer