JEE Mains · Chemistry · STD 12 - 4. d and f- block elements
When \(XO_2\) is fused with an alkali metal hydroxide in presence of an oxidizing agent such as \(KNO_3,\) a dark green product is formed which disproportionates in acidic solution to afford a dark purple solution. \(X\) is
- A \(Mn\)
- B \(Cr\)
- C \(V\)
- D \(Ti\)
Answer & Solution
Correct Answer
(A) \(Mn\)
Step-by-step Solution
Detailed explanation
\(Mn{O_2} + KOH + KN{O_3} \to \mathop {{K_2}Mn{O_4}}\limits_{(dark\,\,green)} + KN{O_2} + {H_2}O\) \(MnO_4^{2 - } + 4{H^ + }\xrightarrow[{tionation}]{{dispropor}}\mathop {2MnO_4^ - }\limits_{(dark\,purple)} + Mn{O_2} + 2{H_2}O\)
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