Answer:
Step-by-step explanation:
Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.
On reactant side:
Oxidation state of chlorine = -1
On product side:
Oxidation state of chlorine = 0
The oxidation state of chlorine increases from -1 to 0. Thus, it is getting oxidized and it undergoes oxidation reaction.