Answer:
is the reducing agent
Explanation:
Oxidation reaction : When there is an increase in oxidation state number.
Reduction reaction : when there is a decrease in oxidation state number.

Fe has undergone oxidation, as its oxidation state is changing from+2 to +3.
Mn has undergone reduction, as its oxidation state is changing from +7 to +2.
The chemical agent which itself get oxidized and reduce others is called reducing agent.
is a reducing agent.
The chemical agent which itself get reduced and oxidize others is called oxidizing agent.
is an oxidizing agent.
.
Answer:
400°C
Explanation:
22,000 cal / (0.11 cal/g°C x 500 g) = 400°C