Question

An iron knife kept dipped in a blue copper sulphate solution

Answer 1

Answer:

Because the iron from the knife displaces the copper from the solution (as iron is more reactive than copper )and forms iron sulphate solution which is green in colour. When an iron knife is dipped is copper sulphate solution, after some time we'll see it has turned light green (from blue) in colour.

Answer 2

Answer:

when iron knife kept dipped in a blue coppet sulphate solution turns into light green solution..iron is more reactive thn copper nd displaces cu+2 from its solution and forms light green ferrous sulphate.