Q. 7.49 - An Introduction to General, Organic, and Biological Chemistry

Question

In the mitochondria of human cells, energy is provided by the oxidation and reduction reactions of the iron ions in the cytochromes in electron transport. Identify each of the following as an oxidation or a reduction: 

a. ${\mathrm{Fe}}^{3+} + {\mathrm{e}}^{-} \to {\mathrm{Fe}}^{2+}$

b. ${\mathrm{Fe}}^{2+} \to {\mathrm{Fe}}^{3+} + {\mathrm{e}}^{-}$

Step-by-Step Solution

Answer

(a) The reaction is reduction reaction.

(b) The reaction is oxidation reaction.

Part (a) Step 1: Given Information

We are given the equations and we have to find out whether these reactions are oxidation or a reduction.

Part (a) Step 2: Explanation

Now, in ${\mathrm{Fe}}^{3+}+ {\mathrm{e}}^{-}\to {\mathrm{Fe}}^{2+}$

$1$ electron is getting reduced from Fe in product side and the reaction in which an atom loses its electron is called reduction.

Hence, the given reaction is reduction.

Part (b) Step 1: Given Information

We are given the equations and we have to find out whether these reactions are oxidation or a reduction.

Part (b) Step 2: Explanation

Now, in ${\mathrm{Fe}}^{2+}\to {\mathrm{Fe}}^{3+} + {\mathrm{e}}^{-}$

$1$electron is getting add in $F{e}^{2+}$ in product side and the reaction in which an atom gains its electron is called oxidation.

Hence, the given reaction is oxidation.