Question

Define variable valency with examples.

Answer 1

Valency is the combining capacity of an element.But sometimes, because of various conditions under which a chemical reaction takes place, the valency of the same element changes. Therefore, metals like lead, tin, copper, mercury, iron etc exhibit variable valency. [1.5 Marks]

Example:
Iron having two valencies 2 and 3. [0.5 Mark]