Question

Reaction of solid $KMnO_4$ with conc. $H_2SO_4$ produces manganese heptoxide $(Mn_2O_7)$ in

• A. solution state
• B. solid state
• C. fine powder
• D. none of these

Answer 1

The Correct Option is A

$KMnO_{4}$ on treatment with conc. $H_{2}SO_{4}$ forms manganese heptoxide via permanganyl sulphate which decomposes explosively on heating $2KMnO_{4} + 3H_{2}SO_{4} \to 2KHSO_{4}+(MnO_{3})_{2} SO_{4} + 2H_{2}O$ $(MnO_{3})_{2} SO_{4} + H_{2}O \to \underset{\text{Red-brown liquid}}{{Mn_{2}O_{7}}}+ H_{2}SO_{4}$ $Mn_{2}O_{7} \to 2MnO_{2}+ \frac{3}{2}O_{2}$ $\therefore\, Mn_{2}O_{7}$ so formed is a red-brown liquid