Question

Preparation of potassium permanganate from MnO\(_2\) involves a two-step process in which the 1^st step is a reaction with KOH and KNO\(_3\) to produce:

• A. \( K_4[{Mn(OH)}_6] \)
• B. \( K_3{MnO}_4 \)
• C. \( {KMnO}_4 \)
• D. \( K_2{MnO}_4 \)

Hint:

In the first step of preparing potassium permanganate, potassium manganate (\( {K}_2{MnO}_4 \)) is formed by reacting manganese dioxide with potassium hydroxide and potassium nitrate. This is then further oxidized to potassium permanganate.

Answer 1

The Correct Option is D

The preparation of potassium permanganate (\( {KMnO}_4 \)) from manganese dioxide (\( {MnO}_2 \)) involves two steps. 
In the first step, \( {MnO}_2 \) reacts with potassium hydroxide (KOH) and potassium nitrate \(KNO_3\) to produce potassium manganate (\( {K}_2{MnO}_4 \)). 
The reaction is: \[ {MnO}_2 + 4 {KOH} + 2 {KNO}_3 \to {K}_2{MnO}_4 + 2 {H}_2{O} \] Thus, the product of the first step is \( \boxed{K_2{MnO}_4} \), corresponding to option (4).