Question:
Salt ‘A’ commonly used in bakery products on heating gets converted into another salt ‘B which itself is used for the removal of hardness of water and a
gas ‘C’ is evolved. The gas ‘C’ when passed through lime water, turns it milky. Identify A, B and C.
Solution:
The salt ‘A’ is sodium hydrogen carbonate (baking soda) and is commonly used in bakeries as a constitutent of baking power. Upon heating, it
changes to sodium carbonate ‘B’ and evolves carbon dioxide gas ‘C’.
Sodium carbonate removes hardness from water while CO2 gas turns lime water milky.