Question

Why blue-coloured copper sulphate solution acquires a green colour when iron filings are added to it ?

Answer 1

When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green

Answer 2

Answer:

This is due to the displacement reaction which occurs in metals .

Displacement reacton occurs when a more reactive metal displaces a less reactive metal.

Iron is more reactive than copper hence it displaces the the copper in the copper sulphate solution and becomes iron sulphate + copper.

Fe    +  ‎CuSO4                    =   FeSo4               + Cu

(Iron)   ( Copper Sulphate)       (Iron sulphate)    (Copper)

Final answer - A blue-coloured copper sulphate solution acquires a green colour when iron filings are added to it as the iron displaces the copper and forms iron sulphate which is green in colour.

Hope it helps :) .