Q15.48P - Chemistry: Molecular Nature Of Matter And Change

Question

Question: Is the organic reactant oxidized, reduced, or neither in each of the following reactions?

Step-by-Step Solution

Answer

1. Reduced
2. oxidized

Both the reactants in the reactions given are oxidized.

Step 1: Introduction

In the case of organic compounds, what is meant by oxidation-reduction, is the change in the number of carbon-heteroatom bonds and carbon-hydrogen bonds. By calculating the difference in the number of carbon-heteroatom bonds of reactant and product or by calculating the difference in the number of carbon-hydrogen bonds in the reactant and product, it can be found out whether the reactant has been oxidized or reduced.

If the number of carbon-heteroatom bonds increases and the number of the carbon-hydrogen bond decreases in going from reactants to the products, the reactant is said to be oxidized.  This is because when carbon makes a bond with more electronegative heteroatom its electron density is decreased, and thus oxidation occurs.

On the other hand, If the number of carbon-heteroatom bonds decreases or the number of the carbon-hydrogen bonds increases in going from reactants to the products, the reactant is said to be reduced. This is because, when carbon makes a bond with hydrogen, it gains electron density, so that it is said to be reduced.

Step 2: Explanation a)

In the given reaction, 1-butyne is giving 1-butene, as the number of C-H bonds is increased in going from reactant to the product, and hence, the reactant is reduced.

Step 3: Explanation b)

In the given reaction, toluene is giving benzoic acid, which is oxidation, as the number of C-H bonds is decreasing.