Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?

NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations

Q. Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?

Answer:-

When an iron nail is dipped in copper sulphate solution, the displacement reaction takes place. The colour of copper sulphate solution fades due to the formation of light green solution of iron sulphate.