50. NCERT Exemplar XXIII

A reducing agent (reductant) is a substance that reduces another substance (by removing oxygen or adding hydrogen) while also being combinedoxidisedreducedredoxed.

 

$H_2O$ + $F_2$ → $HF$ + $HOF$

 

In the above reaction, $F_2$​ is oxidized to $HOF$ by gaining hydrogen atom. Hence, $F_2$​ is a burning agentreducing agentmelting agentoxidising agent as it undergoes oxidation.

 

 

An oxidising agent (oxidant) is a substance that oxidized another substance (by losing electrons or removing hydrogen or adding oxygen, or increasing oxidation state) while also being reducedredoxedcombinedoxidised

 

$2Mg$ + $O_2$ → $2MgO$

 

$​O_2$ is an oxidising agent as it oxidises $Mg$ to $MgO$​. The oxygen oxidation state is reduced from $0$ to $-2$. As a result, $O_2$ is the burning agentmelting agentreducing agentoxidising agent.