D Block Elements

Oxidation of

KMnO%20_%7B4%7D

takes place in all the three medium acidic, basic and the three medium
acidic, basic and oxidation number is different .
In acidic medium :

2%20KMnO%20_%7B4%7D%2B3%20H%20_%7B2%7D%20SO%20_%7B4%7D%20%5Crightarrow%20K%20_%7B2%7D%20SO%20_%7B4%7D%2B2%20MnO%20_%7B4%7D%2B3%20H%20_%7B2%7D%20O%20%2B50

The net reaction is :

MnO%20_%7B4%7D%5E%7B-%7D%20%5Crightarrow%20Mn%20%5E%7B2%2B%7D

change in oxidation number

%3D7-2%3D%2B5

So electrons involved

%3D5%20e%20%5E%7B-%7D

In basic medium :

2%20KMnO%20_%7B4%7D%2B2%20KOH%20%5Crightarrow%202%20K%20_%7B2%7D%20MnO%20_%7B4%7D%2B%20H%20_%7B2%7D%20O%20%2B0

Net reaction is

%5Coverset%7B%2B7%7D%7BMnO%20_%7B4%7D%5E%7B-%7D%7D%20%5Crightarrow%20%5Coverset%7B%2B6%7D%7BMnO%20_%7B4%7D%5E%7B-2%7D%7D

Change in oxidation number

%3D7-6%3D%2B1

So electron involved is

%3D1%20e%20%5E%7B-%7D

In Neutral medium:

2%20KMnO%20_%7B4%7D%2B%20H%20_%7B2%7D%20O%20%5Crightarrow%202%20KOH%20%2B2%20MnO%20_%7B2%7D%2B30

Net

reaction

%5Coverset%7B%2B7%7D%7BMnO%20_%7B4%7D%5E%7B-%7D%7D%20%5Crightarrow%20%5Coverset%7B%2B4%7D%7BMnO%20_%7B2%7D%7D

Change in oxidation no.

%3D7-4%3D%2B3

So electrons involved :

3%20e%20%5E%7B-%7D

Chapter Questions
3 MCQs