The electron ionization of an unknown neutral compound gives this mass spectrum. Which combination of elements most likely comprises the molecule?

Question

Quizplus · Accepted Answer

The peak at m/z = 43 corresponds to the molecular ion (M+) of the compound. The presence of a peak at m/z = 28 suggests the presence of a methyl group (CH3), while the presence of a peak at m/z = 14 suggests the presence of a methylene group (-CH2-). Therefore, the compound likely contains two carbon atoms and at least three hydrogen atoms. The peak at m/z = 42 suggests the presence of a nitrogen atom, and the peak at m/z = 15 suggests the presence of a methyl group attached to a nitrogen atom (CH3N+). Thus, the compound likely contains one nitrogen atom. Combining these observations, the most likely combination of elements is two carbons, three hydrogens, and one nitrogen (Choice A).

The Electron Ionization of an Unknown Neutral Compound Gives This