Question

why does the colour of copper sulphate solution change when an iron nail isn dipped on it? ​

Answer 1

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.

Hope this will help you!!!

Answer 2

it's because of displacement reaction.

first let me tell you about displacement reaction..

displacement reaction is a type of reaction where the more reactive metal displaces the less reactive metal from it's solution.

we know that iron is more reactive metal as compared to copper.

that's why the colour of copper sulphate solution changes when an iron nail is dipped in it. the iron nail displaces copper and form iron sulphate. the copper sulphate solution is blue and when an iron nail is dipped in it, it turns light green.

CuSO4 + Fe ------> FeSo4 + Cu