Question

Potassium manganate `(K_2MnO_4)` is formed when
A. Chlorine is passed into aqueous `KMnO_(4)` is formed when
B. manganese dioxide is fused with potassium hydroxide in air
C. formaldehyde reacts with potassium permanganate in presence of a strong alkali
D. potassium permanganate reacts with conc. Sulphuric acid.

Answer 1

Correct Answer - B::C
(b,c) `2KOH+MnO_(2)+OrarrK_(2)MnO_(4)+H_(2)O`
`HCHO+2KMnO_(4)+2KOHrarr2K_(2)MnO_(4)+H_(2)O+O_(2)`