Chapter 15, Problem 45PP

Interpretation Introduction

Interpretation: The number of carbon atoms present in the given compound under given conditions should be determined.

Concept Introduction:

Mass spectroscopy: It is a form of spectroscopic technique which is used for the elucidation of the molecular formula and molecular weight of the compound, depending upon the mass of the molecule.

The ${\text{(M+1)}}^{\text{+}·}$ peak: It denotes the peak that arises next to molecular ion peak in the mass spectrum. The peak arises due to the presence of the isotope of carbon $\left({}^{\text{13}}\text{C}\right).$

The ${\text{(M+1)}}^{\text{+}·}$ peak in mass spectroscopy is used to explain the number of carbon atoms present in a molecule depending on the abundance of ${\text{(M+1)}}^{\text{+}·}$ peak.

$\frac{\left(\frac{\text{Abundance}\text{of}{\text{(M+1)}}^{\text{+}·}\text{peak}}{\text{Abundance}\text{of}{\text{(M)}}^{\text{+}·}\text{peak}}\right)\times 100\%}{1.1\%}$

Molecular formula: It represents the types of atoms with their total number present in a given molecule.

Molecular ion peak ${\text{(M)}}^{\text{+}·}$: It is defined as the heaviest peak in the IR spectrum of the molecule which represents the largest molecular ion in the given molecule with greater m/z value.

Base peak: It is the tallest peak in the spectrum.

To determine: The number of carbon atoms present in the given compound.