The sum of oxidation state of the metals in Fe(CO)₅, VO²⁺ and WO₃ is ___________.

Solution

Chemistry ma’am · 4 steps

Set each species' charges equal to its overall charge, and remember CO is a neutral ligand.

1. Iron carbonyl. CO is a neutral molecule, so it adds 0. Fe(CO)₅ is neutral overall, so x + 5(0) = 0 gives Fe as 0.
2. Vanadyl ion. Oxygen is -2 and the ion carries a 2+ charge. So x + (-2) = +2, which gives V as +4.
3. Tungsten trioxide. WO₃ is neutral with three oxygens. So x + 3(-2) = 0, which gives W as +6.
4. So. The sum is 0 + 4 + 6 = 10.

The common slip: 8. Setting the sum to 0 for VO²⁺ instead of +2 gives V as +2 and a total of 8, not 10.

The idea to keep. Oxidation states always add up to the overall charge of the species. Neutral ligands like CO count as 0, so metals in carbonyls are usually in the 0 state.

Answer from the NTA final answer key. Solution by PrepWiser.