Question

Calculate the oxidation number of underlined elements in the following compounds:
$K_4\underset{--}{P_2}{O}_7$

• A. 5
• B. 2
• C. 4
• D. -5

Answer 1

The correct option is A 5

$K_4\underset{--}{P_2}{O}_7$
charge on $K=+1$
charge on $O=-2$
Let x be oxidation state of P
$2x+4-2\times 7=0$
$2x=10$
$x=+5$