Question

An element X forms the following compounds with hydrogen, carbon and oxygen :

H₂X, CX₂, XO₂, XO₃

State the three valencies of element X which are illustrated by these compounds.

Answer 1

H₂X:

Element / Ion H X

        Valency  1  2

To stabilize the compound with hydrogen, two atoms of X are required. Therefore, the valency of X in this compound will be two.

CX₂:

Element/ Ion    C    X
     Valency        4     2

To stabilize the compound with carbon, two atoms of X are required. Thus, the valency of X in this compound is two.

XO₂:

Elements / Ion      X   O
    Valency             4   -2

To stabilize this compound with oxygen, four atoms of X are required. Thus, the valency of X in this compound is four.

XO₃:

Elements/ Ion  X  O
      Valency      6  -2

To stabilize this compound with oxygen, six atoms of X are required. Thus, the valency of X in this compound  is six.