Question
" 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
JEE Main
Chemistry
d and f Block Elements
2026
JEE Main 2026 (24 January Shift 2)
JEE Main Chemistry Question (2026) — Solution
Options
- A. purple
- B. orange
- C. yellow
- D. green
Answer
D. green
Step-by-step solution
The lightest element of group 7 (considering transition metals) is manganese (Mn). An oxoanion with Mn in +6 oxidation state is manganate, MnO₄²⁻. In manganate, Mn exhibits +6 oxidation state (where oxygen is -2, so Mn + 4(-2) = -2, giving Mn = +6). The potassium salt K₂MnO₄ (potassium manganate) is green in color. This is distinct from permanganate KMnO₄ (where Mn is +7) which is purple. The characteristic green color of manganate solutions and salts makes this the answer.
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