Question

what changes do you observe when.
a)you add zinc to solution of copper sulphate.
b)you add iron to solution of copper sulphate.

Answer 1

If a displacement reaction has to occur, then a metal more reactive than zinc must be one of the reactant. So, here , on adding zinc to CuSO4 solution, zinc displaces copper from copper sulphate & forms zinc sulphate solution. This is indicated by colour change from blue to colourless.

The iron nail will turn reddish-brown due to deposition of Copper on it. When Iron nail (Ferrum) is dipped in Copper sulphate (CuSO4) there takes reaction between them and coppersulphate change its color from blue to light green.

Answer 2

As both of the metals are reactive then Cu
they will displace them from their salt solution
colour of Cuso4 is blue but when Zinc is added it become colorless
when iron is added to Cuso4 it turns bule to green

Zn + Cuso4(blue) => znso4 (colorless) + Cu
Fe + Cuso4(blue) = > feso4(green) + Cu