Chapter 16, Problem 16.30YT

Interpretation Introduction

Interpretation:

Compute the molecular mass of ${}^{\text{12}}{\text{C}}_{\text{5}}{}^{\text{13}}{\text{C}}^{\text{1}}{\text{H}}_{\text{14}}$. How this compares to m/z for the $\text{M + 1}$ peak in the mass spectrum of hexane is to be explained.

Concept introduction:

The presence of ${}^{\text{13}}\text{C}$ gives rise to an $\text{M + 1}$ peak. The total number of carbon atoms in a molecule can be computed from the intensity of the $\text{M + 1}$ peak relative to that of the ${\text{M}}^{\text{+}}$ peak. The mass of ${}^{\text{12}}\text{C}$ is $\text{12 u}$, and that of ${}^{\text{13}}\text{C}$ is $\text{13 u}$, that is, they differ by $\text{1 u}$.