Question

What is the oxidation number of each phosphorus atom (P) in the compound calcium phosphite, Ca3(PO3)2? (2 points) -2 -3 +3 +6

Answer 1

Ca3(PO3)2

Oxidation numbers:
Ca ---- +2
P----x
O---- -2

+2*3 +x*2 - 2*6 = 0
6 + 2x -12 = 0
2x = 6
x = +3

Oxidation number  of P is +3.