Question

Name a reducing agent that can be used to obtain manganese from manganese dioxide. Write the balanced chemical equation for the reaction.

Answer 1

Hint: Reduction of manganese oxides are classified into two steps. The reduction of oxygen rich oxides to \[{\text{MnO}}\], followed by reduction of \[{\text{Mn}}\] to metallic manganese. A metal is used as a reducing agent.

Complete step by step answer:
- Aluminium powder can be used as a reducing agent to obtain manganese from manganese dioxide. The chemical equation for the reaction is given as below:

     $\mathop {3Mn{O_2}}\limits_{{\text{Manganese Dioxide}}} + \mathop {4Al}\limits_{{\text{Aluminum powder}}} \to \mathop {3Mn}\limits_{{\text{Manganese}}} + \mathop {2A{l_2}{O_3}}\limits_{{\text{Aluminium Oxide}}} $

-It is known that aluminium is more reactive than manganese, therefore when manganese dioxide reacts with aluminium then it results in the formation of aluminium trioxide and manganese. This reaction is also known as a single displacement reaction.
-The elemental aluminium with zero oxidation state reacts with manganese dioxide with +2 oxidation state to reduce oxidation state of manganese to zero and aluminium gets oxidized to +3 state.
-Aluminium is used as a reducing agent in the extraction of metals in those cases where the metal oxide is comparatively more reactive metal than zinc, etc., which cannot be satisfactorily reduced by carbon.
-We should know that aluminium powder is used in the production of many types of explosives and fireworks. It is also employed in the manufacturing of certain types of electronics. Powered aluminium is also used in paints and sealants.

Note: Remember that we need such a reducing agent for this reaction that has greater oxidation potential than that of Manganese metal. Aluminium is very often used to reduce metal oxide because it is a very powerful reducing agent. It has a great affinity for oxygen. Hence, it reduces metallic oxides to metal, with the evolution of a lot of heat.