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.

Why is anhydrous CaCl₂ used in a desiccator. Name one substance which is 'efflorescent'.

Name a deliquescent substance.

Explain the following observations :

(i) Washing-soda become coated with a white powder when left exposed to the atmosphere.

(ii) In the expression anhydrous copper sulphate, what is meant by 'anhydrous'.

(iii) Why is fused calcium chloride or conc. sulphuric acid used in a desiccator.