Question

Why sometimes the valency of chlorine is written as 2?​

Answer 1

Answer:

Explanation:

Valency is the number of hydrogen atoms that combine or displace with another atom to form a compound. One atom of hydrogen combines with one atom of chlorine to form HCl, the valency of chlorine is 1. Two atoms of hydrogen combine with one radical of sulphate to form H2SO4, the valency of sulphate is 2.

Answer 2

It depends on the atom it bonds with. If the other atom is highly electropositive, then Cl can have a -2 valency