Chapter 17, Problem 17.39P

Interpretation Introduction

Interpretation:

It is to be verified whether the nitrile in the given reaction is reduced by calculating the oxidation state of the carbon and the nitrogen atoms of the $\text{C}\equiv \text{N}$ group before and after the reaction has taken place. Further, it is to be determined whether the nitrile gains electrons, and if so, how many.

Concept introduction:

The oxidation state of an atom can be calculated using two steps.

First is to assign the proper number of valence electrons to the atom. In this case, both electrons of a lone pair are assigned to the atom on which they appear. In a covalent bond, all the electrons are assigned to the more electronegative atom. If the two bonded atoms are the same or have comparable electro-negativities, then electrons get divided equally to both the atoms.

Second is by comparing the assigned valence electrons to an atom to the atom’s group number. In this, each excess electron contributes -1 charge while each electron the atom is lacking contributes +1 charge to the oxidation state.

In general, the loss of electrons from the reactant side to the product side is termed as oxidation while the gain of electrons is termed as reduction.