For making a cake, baking powder is taken. If at home, your mother uses baking soda instead of baking powder in cake, (a) how will it affect the taste of the cake and why? (b) how can baking soda be converted into baking powder? (c) what is the role of tartaric acid added to baking soda?

Effect in taste:

• If we use Baking soda instead of baking powder for making the cake, then after the baking process, the taste of the cake will be a little metallic bitter.
• Because baking soda as a base or alkaline ingredient has a naturally bitter taste, also when we heat baking soda /Sodium bicarbonate $\left({\mathrm{NaHCO}}_3\right)$it will form Sodium carbonate$({\mathrm{Na}}_2{\mathrm{CO}}_3)$, which will itself again make the cake bitter in taste.
• The reaction involved here is as follows,

$\underset{(\mathrm{Sodium}\mathrm{bicarbonate})}{2{\mathrm{NaHCO}}_3\left(\mathrm{s}\right)}+\mathrm{Heat}\to \underset{(\mathrm{Sodium}\mathrm{carbonate})}{{\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)}+\underset{(\mathrm{Carbon}\mathrm{dioxide})}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\left(\mathrm{Water}\right)}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Baking soda into Baking powder:

• To convert Baking soda into Baking powder we have to mix baking soda with tartaric acid and starch.
• Baking soda is much stronger than baking powder.
• So for making baking powder we have to use 1 part of baking soda and 2 parts of tartaric acid.

Role of tartaric acid:

• Use of baking soda while baking or making cake, makes the cake taste bitter due to the formation of Sodium carbonate during heating.
• Hence, to neutralize the formed sodium carbonate and its bitter taste, we use tartaric acid.
• As an acid tartaric acid neutralizes the base effect of Sodium bicarbonate.