Question

How is $KMn{{O}_{4}}$ prepared from pyrolusite ore?

Answer 1

Hint: The name of $KMn{{O}_{4}}$ is potassium permanganate and it is prepared from the pyrolusite ore whose formula is $Mn{{O}_{2}}$. There are some steps that are followed in which alkali metal hydroxide and oxidizing agents are also required.

Complete answer:
Pyrolusite ore is an important ore in which we can prepare potassium permanganate as Potassium permanganate whose formula is $KMn{{O}_{4}}$ and is an inorganic compound. Some other names of potassium permanganate are Condy’s crystals and permanganate of potash.
As we already know, manganese dioxide ($Mn{{O}_{2}}$), which can also be found in the mineral pyrolusite, is used to make potassium permanganate ($KMn{{O}_{4}}$ ).
The pyrolusite ore is heated in air or with another type of oxygen, such as potassium nitrate or potassium chlorate, after being fused with an alkali such as potassium hydroxide. Potassium manganate is produced as a result of this process. The reaction is given below:
$2Mn{{O}_{2}}+4KOH+{{O}_{2}}\to 2{{K}_{2}}Mn{{O}_{4}}+2{{H}_{2}}O$
This potassium manganate is now electrolytically oxidized in alkaline media to produce potassium permanganate. The reaction is given below:
$2{{K}_{2}}Mn{{O}_{4}}+2{{H}_{2}}O\to 2KMn{{O}_{4}}+2KOH+{{H}_{2}}$
Hence, these are the steps that are used to convert pyrolusite ore to potassium permanganate.

Additional information:
Since potassium permanganate is a powerful oxidizing agent, it can be used as an oxidant in a broad range of chemical reactions. When conducting a redox reaction with potassium permanganate, the dark purple solution becomes colorless and then into a brown solution, demonstrating its oxidizing ability.

Note:
We should also be aware that under acidic conditions, potassium manganate may be oxidized by chlorine or disproportion. The following is the chlorine oxidation reaction:
 $2{{K}_{2}}Mn{{O}_{4}}+C{{l}_{2}}\to 2KMn{{O}_{4}}+2KCl$