Question

What is the oxidation number of phosphorus (P) in sodium phosphate (Na3PO4)?

Answer 1

Na⁺¹₃P⁺⁵O⁻²₄

+1*3 + (+5) + (-2*4) = 0

Answer 2

Let the oxidation number of P be x.

We know that oxidation number of Na= +1, O= -2

therefore, 3*1 + x+ 4* -2 = 0 (net charge on the molecule)

3 + x - 8 =0

x = +5

therefore, the answer is C)+5