When an oxide of manganese (A) is fused with KOH in the presence of an oxidising agent and dissolved in water, it gives a dark green solution of compound (B). Compound (B) disproportionates in neutral or acidic (C ) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds A to D and also explain the reactions involved.

Options

A. `{:(P,Q,R,S),(MnO_4^(-) , KIO_3 , MnO_2 , K_2MnO_4):}`
B. `{:(P,Q,R,S),(MnO_2 , K_2MnO_4 , MnO_4^(-) , KIO_3):}`
C. `{:(P,Q,R,S),(MnO_2 , MnO_4^(-) , K_2MnO_4 , KIO_3):}`
D. `{:(P,Q,R,S),(K_2MnO_4 , MnO_2 , MnO_4^(-) , KIO_3):}`

Answer

B

Explanation

P=`MnO_2` , Q=`K_2MnO_4`, R=`KMnO_4`, S=`KIO_3`
`underset"(P)"(2MnO_2) + 4KOH + O_2 to underset"(Q)"(2K_2MnO_4) + 2H_2O`
`3MnO_4^(2-) + 4H^(+) to underset"(R )"(2MnO_4^(-)) + MnO_2 + 2H_2O`
`2MnO_4^(-) + H_2O + KI to underset"(P)"(2MnO_2) + 2OH^(-) + underset"(S)"(KIO_3)`