What happens when piece of
(a) zinc metal is added to copper sulphate solution ?
(b) aluminium metal is added to dilute hydrochloric acid ?
(c) silver metal is added to copper sulphate solution ?
Also write the balanced chemical equation if the reaction occurs.

Explanation

(a) Blue colour of `CuSO_(4)` solution disappears.
Reason Zinc reacts with copper sulphate to form colourless zinc sulphate solution and solid copper in deposited form as Zn is more reactive than Cu, so, displaces Cu from `CuSO_(4)` solution.
`underset(underset("(grey)")("Zinc"))(Zn(s))+underset(underset(underset("(blue)")("sulphate"))("Copper"))(CuSO_(4)(aq)) to underset(underset("(colourless )")("Zinc sulphate"))(ZnSO_(4)(aq))+underset(underset("(brown)")("Copper"))(Cu(s))`
(b) Hydrogen gas is evolved.
Reason Aluminium reacts with dilute hydrochloric acid to form aluminium chloride and hydrogen gas.
`underset("Aluminium")(2Al(s))+underset(underset("acid")("Hydrochloric"))(6HCl(aq)) to underset(underset("chloride")("Aluminium"))(2AlCl_(3)(aq))+underset("Hydrogen")(3H_(2)(g))`
(c) No reaction occurs.
Reason Silver metal is less reacti than copper, therefore, it cannot displace copper from copper sulphate solution.
`underset("Silver")(Ag(s))+underset(underset("suphate")("Copper"))(CuSO_(4)(aq)) to "No reaction"`