Question

Among the following, identify the species with an atom in
+6 oxidation state
(a) MnO₄⁻ (b) Cr(CN)₆³⁻
(c) NiF₆²⁻
6 (d) CrO₂Cl₂

Answer 1

Among the following species with an atom in +6 oxidation number is CrO2Cl2

1) In MnO₄⁻

the oxidation number of Mn is

1×(Mn) + 4×(-2) = -1

Mn -8= -1

Mn = -1+8

Mn =+7

2) In Cr(CN)₆³⁻

the oxidation number of Cr is

1×(Cr) + 6(-1) = -3

Cr -6 = -3

Cr =-3+6

Cr = +3

3) In NiF₆²⁻

the oxidation number of Ni is

1×(Ni) + 6×(-1) = -2

Ni -6=-2

Ni= -2+6

Ni= +4

4) In CrO₂Cl₂

the oxidation number of Cr is

1×(Cr) + 2×(-2) + 2×(-1) = 0

Cr -4-2=0

Cr = +6

so option (d) is the right answer

Answer 2

Among the following species,the one with an atom in +6 oxidation state is CrO₂Cl₂

1. In MnO₄⁻ , the oxidation number of Mn is +7

2. In Cr(CN)₆³⁻, the oxidation number of Cr is +3

3. In NiF₆²⁻, the oxidation number of Ni is +4

4. In CrO₂Cl₂, the oxidation number of Cr is +6

5. So, (d) is the correct answer