Help with oxidation number of the transition metals!?

When a Cl is bonded to a metal, its charge is -1. When an O is bonded to a metal, its charge is -2. In a compound the sum of the charges is 0. In an ion, the sum of the charges is the charge of the ion.


1. Fe2Cl6

Cl6 = -6
2 Fe = +6
Fe = +3

2.VO2+

O2 = -4
V + -4 = +1
V = +5

3.VO3+

O3 = -6
V + -6 = +1
V = +7

4. [CrCL(H2O)5]2+

In this ion, one Cr is bonded to one Cl. Cl is -1

Cr + -1 = +2
Cr = +3

Do you mean VO2^+ or VO^2+? Same for VO3^+ or VO^3+. I'm going to assume VO^2+ and VO^3+, as these fit better with vanadium ions.

Fe is in the +3 state. Cl is -1 when bound to low electronegativity elements. 2Fe + 6Cl = 0, so 2Fe = -6(-1) = +6, so Fe = +3

In VO^2+, O is -2, so V is +4 to balance.

In VO^3+, vanadium must be +5.

In [CrCl(H2O)5]^2+, H2O is 0 and Cl is again -1. This leads to Cr being +3.

1. Fe+3
2. V+6
3. V+7
4. Cr+3