Question

Determine the oxidation number of Phosphorous in $H_{3}P{O}_4$.

• A. $+5$
• B. $+4$
• C. $+3$
• D. $+2$

Answer 1

The correct option is A

$+5$

We know that the oxidation number of $H=+1$ and $O=-2$.
Consider the oxidation number of $P$ be $x$

$3+x+4(-2)=0$
$\Rightarrow x=+5$

Thus the oxidation number of phosphorous in $H_{3}P{O}_4$ is $+5$.