Question

Rohan placed an iron nail in copper sulphate solution.

(a) What will he observe after one hour?

(b) What will be the colour change?

(c) Give reason for the change in colour observed.

(d) Write the chemical equation for the reaction.

Answer 1

• When an iron nail is placed in copper sulfate solution iron displaces copper to form ferrous sulfate and copper metal.
• We can observe the formation of copper precipitates red in color and the color of the solution changes to a green color.
• Hence, the following will be the answers.
• (a) He will observe red precipitates of metallic copper as the copper is displaced by iron in the copper sulfate solution.
• (b) The color of the solution will change from blue to green.
• (c) As the solution will become ferrous sulfate that is green from copper sulfate that is blue in color, Rohan will observe the change in the color of the solution.
• (d) The chemical equation for the reaction can be written as follows.
• $\underset{\mathrm{Iron}}{\mathrm{Fe}\left(\mathrm{s}\right)}+\underset{\mathrm{Copper}\mathrm{sulphate}}{\mathrm{CuSO}4\left(\mathrm{aq}\right)}\to \underset{\mathrm{Ferrous}\mathrm{sulphate}}{\mathrm{FeSO}4\left(\mathrm{aq}\right)}+\underset{\mathrm{Copper}}{\mathrm{Cu}\left(\mathrm{s}\right)}$