Question

Blue colored X changes to white colored Y on heating and in the presence of the moisture Y gives blue colored X. This is because ____

• A. X is NaCl
• B. X is the bleaching powder
• C. X has some water of crystallization
• D. None of the above

Answer 1

The correct option is C

X has some water of crystallization

This is because X has some water crystallization. When X is heated, the water molecules disappear and X loses its blue color and become Y (anhydrous). Again when Y is moistened i.e. reacted with water, X takes some water molecule as water of crystallization and blue color reappears.