Question

An element X forms an ion having a charge of $+4$ while another element Y forms an ion having a charge of $-2$. What will be the chemical formula of the compound formed by the combination of X and Y?

• A. $X{Y}_4$
• B. $X{Y}_2$
• C. $XY$
• D. $X_{2}Y$

Answer 1

The correct option is B $X{Y}_2$

The valency of X is $+4$ and that of Y is $-2$.

Symbol: X Y
$\searrow \swarrow$
Valency: 4 2

$\therefore$ Formula of the compound: $X_2{Y}_4$

In the chemical formula of a compound, the elements are written in their simple whole number ratio.

$\therefore$ Chemical formula of the compound is $X{Y}_2$.