Explain why? (a) Common salt becomes sticky during the rainy season

Explain why?
(a) Common salt becomes sticky during the rainy season.
(b) Blue vitriol changes to white upon heating.

(a) Common salt contains impurity of magnesium chloride (MgCl2) which is of deliquescent nature. When exposed to atmosphere, it becomes moist. Therefore, common salt becomes sticky during the rainy season.

(b) Blue vitriol (CuSO45H2O) during heating changes to a anhydrous copper sulphate (CuSO4) which is white in colour.