Question

We can show that iron is more reactive than copper :
(1) by preparing copper sulphate solution and dipping the iron strip in it.
(2) by dipping both the strips in water for some time.
(3) by preparing iron sulphate solution and dipping copper strip in it.
(4) by heating both iron and copper strip.

Answer 1

When an iron strip is dipped into a blue solution of copper sulphate, it turns the colour of the solution from blue to green due to the formation of ferrous sulphate. It happens because iron displaces the copper from copper sulphate solution and forms iron sulphate. This shows that iron is more reactive than copper. The reaction involved is as follows:

$\mathrm{Fe}\left(\mathrm{s}\right)+{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)\to {\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right)$

Hence, the correct answer is option 1.