Question

Oxidation state of phosphorus in cyclotrimetaphosphoric acid is:

• A. 5
• B. 4
• C. 3
• D. none of these

Answer 1

Answer: (A)

5

Formula of Trimetaphosphoric acid $(HP{O}_3{)}_3$

Oxidation state of $P$ is: (Refer to Image)

$3(+1+x+3(-2\left)\right)=0$

$\Rightarrow x-6+1=0$

$\Rightarrow x=+5$

$+5$ is the oxidation state of phosphorus in Trimetaphosphoric acid.