<u>Answer:</u> The oxidizing agent in the given reaction will be ion.
<u>Explanation:</u>
Oxidizing agent are defined as the species which oxidize the other species and itself gets reduced. It undergoes a reduction reaction. The reduction reaction is defined as the reaction in which a specie gains electrons. The oxidation state of the specie gets reduced.
In the given chemical equation:
Reactant side:
Oxidation state of hydrogen = +1
Oxidation state of oxygen = -2
Oxidation state of Tin = 0
Oxidation state of chlorine = -1
Oxidation state of nitrogen = +5
Product side:
Oxidation state of hydrogen = +1
Oxidation state of oxygen = -2
Oxidation state of Tin = +6
Oxidation state of chlorine = -1
Oxidation state of nitrogen = +4
As, the oxidation state of nitrogen is getting reduced. Hence, it is getting reduced and is considered as an oxidizing agent.