Question

The valency of sulphate ion is_____

Answer 1

Definition of Valency

• Valency is the number of electrons in its outermost shell.
• Valency can also be defined as the number of electrons needed to complete the octet configuration or to fill the outermost shell.
• It is the number of electrons of an atom which uses to combine with atoms of another element.
• It is the combining power of an element.
• In an atom, the valence electrons are the electrons that can be used in combining with other atoms. they are lying in the valance shells(orbitals of the outermost shell).
• For example, Hydrogen has 1 electron, and its valency is one, one electron is needed to complete its outermost shell.

Sulphate ion

• It is an ion of sulphur oxide carrying a double negative charge. ${\left({\mathrm{SO}}_4\right)}^{-2}$ accepts 2 electrons from others.
• Total valency can be calculated by adding the valency of the sulphur and oxygen. S= +6, O= -2. Total valency= +6 + (4x-2) = +6-8 = -2
• So the valency of sulphate ion is -2

The valency of sulphate ion is -2