Question

Question 38.
Salt A commonly used in bakery products on heating gets converted into another salt B which itself is used for 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

Answer 1

Salt A is sodium bicarbonate ${\text{NaHCO}}_3$ (as it is used in bakery products and gives ${\text{Na}}_2{\text{CO}}_3$ on heating). Salt B is sodium carbonate ${\text{Na}}_2{\text{CO}}_3$ (it is used for removal of hardness of water). Gas C is carbon dioxide ${\text{CO}}_2$ (as it turns lime water milky).
This can be shown as follows:

$2{\text{NaHCO}}_3\stackrel{\text{Heat}}{\to }{\text{Na}}_2{\text{CO}}_3+{\text{H}}_2\text{O}+{\text{CO}}_2$