Question

The oxidation number of phosphorus in $M{g}_2{P}_2{O}_7$ is:

• A. 3
• B. 2
• C. 5
• D. -3

Answer 1

The correct option is C 5

$M{g}_2{P}_2{O}_7$
Let x be the oxidation state of P,
Mg carries + 2 charge and each oxygen carries -2 charge
2(+2) + 2x + 7 (-2) = 0
$\therefore x=+5$

So, oxidation number of P = + 5