Question

Which of following is correct regarding the following compound?

• A. Oxidation state of phosphorous is +4.
• B. Oxidation state of phosphorous is +5.
• C. Oxidation state of phosphorous is +6.
• D. Oxidation state of phosphorous is +3.

Answer 1

The correct option is B Oxidation state of phosphorous is +5.

Consider the oxidation number of $P$ as $x$.
Valency of each oxygen which is having single bond with $P$ will be considered as -1 and which is having double bond will be considered -2.
We can see molecule overall is neutral.
Valency of one oxygen which is having one-one bond with each $P$ will be considered -2.
so,
$2x+4\times (-1)+3\times (-2)=0$
$x=+5$

Thus, oxidation state of $P$ is $+5$.