Question

13. How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Fe(s) + I'(aq) 12(s) + Fe3+(aq) A) 1 B) 2 C) 6 D) 3 E) 4

Answer 1

Answer : The correct option is, (C) 6

Explanation :

Oxidation-reduction reaction : It is a reaction in which oxidation and reduction reaction occur simultaneously.

Oxidation reaction : It is the reaction in which a substance looses its electrons. In this oxidation state increases.

Reduction reaction : It is the reaction in which a substance gains electrons. In this oxidation state decreases.

The given unbalanced chemical reaction is,

$Fe(s)+I^-(aq)\rightarrow I_2(s)+Fe^{3+}(aq)$

Half reactions of oxidation and reduction are :

Oxidation : $Fe(s)\rightarrow Fe^{3+}+3e^-$        ......(1)

Reduction : $2I^-(aq)+2e^-\rightarrow I_2$         .......(2)

In order to balance the electrons, we multiply equation 1 by 2 and equation 2 by 3, we get:

Oxidation : $2Fe(s)\rightarrow 2Fe^{3+}+6e^-$        ......(1)

Reduction : $6I^-(aq)+6e^-\rightarrow 3I_2$         .......(2)

The overall balanced chemical reaction will be:

$2Fe(s)+6I^-(aq)\rightarrow 3I_2(s)+2Fe^{3+}(aq)$

From this reaction we conclude that the electrons are getting transferred from iron to iodine and the number of electrons transferred are 6 electrons.

Hence, the correct option is, (C) 6