Chapter 8.5, Problem 2E

(a)

Interpretation Introduction

Interpretation: In the mass spectrum of 2,2-dimethylpropane, it is given that the base peak occurs at $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ 57, peaks of moderate intensity are found at $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ 29 and 43, and a weak peak occurs at $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ 15, from which $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ for $P^{+}$ is to be determined.

Concept Introduction: The chemical formula for 2,2-dimethylpropane, which is also known an Neopentane, is $C_5{H}_{12}$ . This is a highly inflammable gas under normal conditions of temperature and pressure, and under lower temperatures, it could easily get converted to a highly volatile liquid

(b)

Interpretation Introduction

Interpretation: In the mass spectrum of 2,2-dimethylpropane, it is given that the base peak occurs at $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ 57, peaks of moderate intensity are found at $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ 29 and 43, and a weak peak occurs at $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$z$}\right.$ 15, for which using curved arrows to symbolize the flow or electrons, the specific fragmentation peaks needs to be accounted.

Concept Introduction: Fragmentation is the process in which energetically unstable molecular ions gets dissociated, when these molecules are passed through the ionization chamber of a mass spectrometer.