Question

Copper having electronic configuration 2,8,18,1 exhibits variable valency. Give a reason for the same and name the compound CuCI and CuCl₂.

Answer 1

Copper exhibit valency ‘1’ and ‘2’ i.e. has variable valency reason for variable valency:
Valency is the number of electrons lost or gained from the outer shell of an atom of an element – during the chemical reaction. Variation in this gain or loss results in ‘variable valency’.
Lower valency ends with – ous
Higher valency ends with – ic
CuCI is named as cuprous chloride (lower valency)
OR
Cu [I] Cl i.e. Copper [I] chloride and CuCl₂ – Cupric chloride (higher valency) i.e. Copper [II] chloride Cu[II]Cl₂