The crystals of a compound A on keeping in air get converted into a white powder. Its solution in water gives blue colour with red litmus. It is used to remove permanent hardness from water.
(a) Identify the substance. Write chemical formula for its crystalline from.
(b) Form the given information, identify the nature of the substance.
(c ) Write two more uses of the substance.

Explanation

(a) The substance is washing soda. Its chemical formula is `Na_(2)CO_(3)10H_(2)O.`
(b) Since the awueous solution of the substance in water turns red litmus blue, it is of basic nature.
(c ) (i) It is used in laundry for washing clothes.
(ii) It is used in the manufacture of glass, paper and chemicals like caustic soda (NaOH), and borax `(Na_(2)B_(4)O_(7))` etc.