Question

In substance $Mg\left({HXO}_3\right)$, the oxidation number of X is :-

• A. $0$
• B. $+2$
• C. $+3$
• D. $+4$

Answer 1

Answer: (C)

$+3$

Molecular formula $=Mg\left(HX{O}_3\right)$

Overall charge on compound $=0$

Oxidation no. of oxygen in compound $=-2$

Oxidation no. of hydrogen in compound $=+1$

Oxidation no. of magnesium im compound $=+2$

Let the oxidation no. of X be x.

Sum of oxidation no. of atoms = overall charge on atom

$\Rightarrow 1\times (+2)+1\times (+1)+1\times x+3\times (-2)=0$

$\Rightarrow 2+1+x-6=0$

$\Rightarrow x-3=0$

$\Rightarrow x=3$

Hence, the oxidation number of X is 3.