How baking soda helps in baking?

Sodium Bicarbonate NaHCO₃ is known as baking soda. It is also manufactured by Solvay process. In Laboratory, it can be prepared by saturating aqueous solution of sodium carbonate with carbon dioxide.

Na₂CO₃ + CO₂ + H₂O → 2NaHCO₃

Baking soda is a white solid. It is sparingly soluble in water and the solution is slightly alkaline which turn red litmus blue.

Baking powder is a mixture of sodium bicarbonate and tartaric acid. Baking powder is used in aerated drinks and as an additive in food stuff to make it soft. Sodium carbonate produced during baking is neutralised by tartaric acid present in baking powder.

How baking soda helps in baking?

When it is heated, it decomposes with the evolution of carbon dioxide gas. Hence, it is used as a constituent of baking powder to soften the dough and to aerate the drinks. The evolution of carbon dioxide also makes it useful for fire extinguishers.

It gives brisk effervescence with acids due to the liberation of carbon dioxide

Baking Soda can extinguish fire

Baking soda is also an excellent fire extinguisher because the chemistry of this salt at high temperatures diminishes the oxygen environment. How does this occur? While NaHCO3 is a stable ionic solid at room temperature, at the high temperatures typical of fires NaHCO3 (s) undergoes thermal decomposition (i.e., a heat-activated reaction) to produce carbon dioxide gas as one of the by-products. Just as in the case of CO2 fire extinguishers, the CO2 gas produced by the decomposition of baking soda creates an atmosphere of reduced oxygen content that aids in extinguishing a fire.