How does an increase in temperature affect :

(i) the solubility of NaCl
(ii) the solubility of CaSO₄ in water ?

Give reasons for the following :

(i) table salt becomes moist and sticky during the rainy season.

(ii) a white powder forms on the surface of washing soda crystals which are left exposed to the air.

Name a salt

(a) which contains water of crystallization

(b) which does not contain.

Name a deliquescent substance.