Question

Ravi placed a zinc plate in a glass container having a blue coloured solution of a metal sulphate MSO₄ for a considerable time. He found that the blue colour of solution got lighter and lighter, and finally the solution became colourless. A red-brown deposit was also formed on the zinc plate.
(a) Which metal, zinc or M, occurs lower in the reactivity series?
​(b) Name the substance which forms colourless solution.

Answer 1

When Ravi places zinc plate in a blue colored solution of metal sulphate, he found that colour of the solution is fading that means zinc is more reactive than that metal and displacing it from the solution. As the solution becomes colourless after some time it shows that metal M will be copper.

(a) Zinc is more reactive than metal M.

(b) Due to the formation of zinc sulphate solution becomes colourless.
$\mathrm{Zn}+\underset{\mathrm{blue}}{{\mathrm{CuSO}}_4}\to \underset{\mathrm{colourless}}{{\mathrm{ZnSO}}_4}+\mathrm{Cu}$