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:
$\begin{array}{ccc}\mathrm{Element}/\mathrm{Ion}& \mathrm{H}& \mathrm{X}\\ \mathrm{Valency}& 1& 2\end{array}$
To stabilize the compound with hydrogen, two atoms of X are required. Therefore, the valency of X in this compound will be two.

CX₂:
$\begin{array}{ccc}\mathrm{Element}/\mathrm{Ion}& \mathrm{C}& \mathrm{X}\\ \mathrm{Valency}& 4& 2\end{array}$
To stabilize the compound with carbon, two atoms of X are required. Thus, the valency of X in this compound is two.

XO₂:
$\begin{array}{ccc}\mathrm{Element}/\mathrm{Ion}& \mathrm{X}& \mathrm{O}\\ \mathrm{Valency}& 4& -2\end{array}$
To stabilize this compound with oxygen, four atoms of X are required. Thus, the valency of X in this compound is four.

XO₃:
$\begin{array}{ccc}\mathrm{Element}/\mathrm{Ion}& \mathrm{X}& \mathrm{O}\\ \mathrm{Valency}& 6& -2\end{array}$
To stabilize this compound with oxygen, six atoms of X are required. Thus, the valency of X in this compound is six.