" X " is an oxoanion of the lightest element of group 7 (in the periodic table). The metal is in +6 oxidation state in " X ". The color of the potassium salt of X is

Q. " X " is an oxoanion of the lightest element of group 7 (in the periodic table). The metal is in +6 oxidation state in " X ". The color of the potassium salt of X is

(A) purple

(B) orange

(D) green

Correct Answer: green

Explanation

Group 7 elements are Mn, Tc and Re. The lightest element of this group is manganese.

In +6 oxidation state, manganese forms the oxoanion manganate:

MnO₄²⁻

The potassium salt of this oxoanion is potassium manganate, K₂MnO₄.

Potassium manganate is characteristically green in colour.

Hence, the correct answer is option (D).

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