Question

Iron nail are placed in copper sulphate tell reaction and equations in it

Answer 1

When iron nails are kept dipped in copper sulphate solution for about 30 minutes, the blue colour of the aqueous copper sulphate would slowly fade to become green and a brown deposition would be seen on the iron nails.
It can be summed up as the following reaction-

CuSO4(blue)(aq) + Fe(gray)(s) → FeSO4(green)(aq) + Cu(brown)(s)

Answer 2

it will be displacement reaction
eq-fe+cuso4 > feso4+ cu