Question

(A) A solution of substance X is used for white washing. What is the substance X? State the chem reaction of Xwith water.
(B) why does the colour of copper sulphate solution change when an iron nail is deeped in it?

Answer 1

A - The substance ‘X’ which is used in white washing is calcium oxide or quick lime and its formula is CaO.

B -  When an iron nail dipped in the copper sulphate solution than iron displaces copper from the copper sulphate because iron is more reactive than copper. Therefore the colour of the copper sulphate solution changes.

Answer 2

A. the x substance is calcium oxide.

calcium oxide + water ---------calcium hydroxide

B. due to occurrence of the displacement reaction in it. highly reactive metal displaces low reactive metal from the salt solution.