Question

Explain why when an iron nail is kept in copper sulphate solution blue colour of the solution fades and iron articles became brownish

Answer 1

since iron is more reactive than copper so it displaces it from it partner which is sulphate and it take it place therefore copper sulphate solution blue colour fades away
iron articles become brownish because iron displaces copper from its partner and copper now set on the iron nail.
hope this will help you