Question

The valency of sulphate ion is _____.

Answer 1

Sulphate ion:

• A sulphate ion is a polyatomic ion composed of sulphur and oxygen atoms with formula ${{\mathbf{SO}}_{\mathbf{4}}}^{\mathbf{2}\mathbf{-}}$.
• The molecular geometry of sulphate ion is tetrahedral where sulphur is at the centre (central metal atom) and is surrounded by four oxygen atoms. Considering the bonding, two of the oxygen atoms form a double bond with sulphur ($\mathbf{S}\mathbf{=}\mathbf{O}$) and the other two form single bonds ($\mathbf{S}\mathbf{-}\mathbf{O}\mathbf{-}$).
• 

Thus, the valency of sulphate ion is -2 .