Question

The oxidation states of $P$ atom in $POC{l}_3,H_{2}P{O}_3$ and $H_4{P}_2{O}_6$, respectively are

• A. +5, +4, +4
• B. +5, +5, +4
• C. +4, +4, +5
• D. +3, +4, +5

Answer 1

Answer: (A)

Let the oxidation state of P-atom in $POC{l}_3,H_{2}P{O}_3$ and $H_4{P}_2{O}_6$ be $x$.
$(i)POC{I}_3$
$x+1(-2)+3(-l)=0$
$x-2-3=0$
$x=+5$
$(ii)H_{2}P{O}_3$
$2(1)+x+3(-2)=0$
$2+x-6=0$
$x=+4$
$(iii)H_4{P}_2{O}_6$
$4(1)+2x+6(-2)=0$
$4+2x-12=0$
$2x=8$
$x=+4$