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Which of the following name formula combinations is not correct? (1) K2[Pt(CN)4] - Potassium tetracyanoplatinate (II) ion (2) [Mn(CN)5]2- - Pentacyanomanganate (II) ion (3) K[Cr(NH3)2Cl4] - Potassium diamminetetrachlorochromate (III) (4) [Co(NH3)4(H2O)]SO4 - Magnetron value.

1. K2[Pt(CN)4] - Potassium tetracyanoplatinate (II) ion
2. [Mn(CN)5]2- - Pentacyanomanganate (II) ion
3. K[Cr(NH3)2Cl4] - Potassium diamminetetrachlorochromate (III)
4. [Co(NH3)4(H2O)]SO4 - Magnetron value.

Correct answer: [Mn(CN)5]2- - Pentacyanomanganate (II) ion

Solution

The name 'Pentacyanomanganate (II) ion' is incorrect because the oxidation state of manganese in this complex is actually +3, not +2, which should be reflected in the name.

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