Final answer:
The oxidation state of phosphorus in PO3^3- is +3. This is determined by adding the oxidation states of the oxygen atoms (-6) to the overall charge of the ion (-3) and solving for the unknown oxidation state of P.
Step-by-step explanation:
To determine the oxidation state of phosphorus (P) in PO33-, we can use the concept that the sum of oxidation states of all atoms in a polyatomic ion equals the charge of the ion. Oxygen typically has an oxidation state of -2. Since there are three oxygen atoms, we would have a total of -6. The overall charge of the ion is -3, which means the phosphorus must have an oxidation state which, when added to -6, equals -3.
Let's denote the oxidation state of phosphorus as x. So the equation based on the oxidation states would be:
Therefore:
- x - 6 = -3
- x = -3 + 6
- x = 3
The oxidation state of phosphorus in PO33- is therefore +3.