Question

when a iron nail added to blue colour solution of copper sulphate solution changes to green colours with brownish precipirate why ?​

Answer 1

Answer:

When an iron nail is dipped in copper sulphate solution, a brown coating of copper is formed in the surface of iron and the colour of copper sulphate solution changes from blue to pale green. The reaction shows that iron is more reactive than copper because it displaces copper from the copper sulphate solution.

Answer 2

Answer:

When a iron nail is added to blue colour solution of copper sulphate solution, it changes to green colour with brownish nail, after few days, because in the reactivity series, Iron is above Copper. That's why Iron replaces Copper and forms Iron Sulphide.

The equation is given below:-

Fe + CuSO4 = FeSO4 + Cu