Question

Potassium manganate `(K_(2)MnO_(4))` is formed when:
A. potassium permanganate reacts with formaldehyde in acidic medium
B. Manganese dioxide is fused with potassium hydroxide in air.
C. Manganese hydroxide reats with `K_(2)O_(2)` in alkaline medium.
D. Potassium permanganate is heated at 750K

Answer 1

Correct Answer - B::C::D
(A) `5HCHO+MnO_(4)^(-)+6H^(+)to2Mn^(2+)+5HCOOH+3H_(2)O`
(B) `4KOH+2MnO_(2)("Manganese dioxide")+O_(2)to2K_(2)MnO_(4) ("potassium manganate")+2H_(2)O`
(C) `Mn(OH)_(2)+O_(2)^(2-)toMnO_(4)^(2-)("Mangnate")+MnO_(2)+O_(2)`.
(D) `2KMnO_(4)overset(750K)toK_(2)MnO_(4)` (potassium mangnate) `+MnO_(2)+O_(2)`.