Question

Assign oxidation numbers to the underlined element in the following species:

 NaH₂PO₄

Answer 1

Let the oxidation number of P be x.

We know that,

Oxidation number of Na = +1

Oxidation number of H = +1

Oxidation number of O = - 2

⇒

+1	+1	x	-2
Na	H2	P	O4

 

Then, we have

1(+1) + 2(+1) + 1(x) + 4(-2) = 0

⇒ 1 + 2 + x - 8 = 0

⇒ x = + 5

Hence, the oxidation number of P is + 5.