Question

Which of the reactant acts as oxidant or reductant if any:
\[KI{O_3} + 5KI + 6HCl \to 3{I_2} + 6KCl + 3{H_2}O\]
(A) \[KI{O_3}\] is oxidant
(B) \[KI\] is reductant
(C) Both of these
(D) None of these

Answer 1

Hint: In order to find which of the following is oxidant and reductant in the given equation, we must first have an idea about what an oxidant and reductant is. Oxidant which is known as the Oxidizing agent is the substance which can Oxidize the other chemical species present in the reaction and it will get reduced. Reductant which is known as the reducing agent is the substance which can reduce other chemical species present in the reaction and it will get oxidized by itself.

Complete step by step answer:
- Let us first see what an oxidant is. Oxidant is the substance which can Oxidize the other chemical species present in the reaction and it will get reduced.
- Oxidant will increase the oxidation state of the other substance, while the oxidation state of it will be decreased.
- Let us now see what is a reductant. Reductant is the substance which can reduce the other chemical species present in the reaction and it will get oxidized.
- Reductant will decrease the oxidation state of the other substance, while the oxidation state of it will be increased.
- Now let us move onto the given question. In the equation given below let us find which is the oxidant and which is the reductant.
\[KI{O_3} + 5KI + 6HCl \to 3{I_2} + 6KCl + 3{H_2}O\]
- When \[KI\] is converted to \[{I_2}\], the oxidation state is changed from the -1 to 0. This means that the oxidation reaction is taking place and therefore, \[KI\] is the reductant.
- When \[KI{O_3}\] is converted to \[{I_2}\], the oxidation state is changed from the +5 to 0. This means that the reduction reaction is taking place and therefore, \[KI{O_3}\] is the oxidant.
As the \[KI{O_3}\] is oxidant and \[KI\] is the reductant, we can say that both the options are correct. The correct option is option “C” .

Note: Some of the application of the oxidising agent is that they can be used for:
- purification of water.
- bleaching of fabrics.
- Combustion of fuel
- many biological processes.