Give the ion that corresponds a m/z ratio of 31 in a mass spectrum of 1-butanol.

Question

Quizplus · Accepted Answer

The m/z ratio of 31 corresponds to the fragment ion CH3O+ in the mass spectrum of 1-butanol. The structure of 1-butanol is CH3CH2CH2CH2OH. The most likely fragmentation pathway for this molecule is a loss of a methyl group (CH3) to form a carbocation (CH3CH2CH2CH2+) followed by a loss of a water molecule (H2O) to form the CH3CH2CH2+ ion. This ion can then lose a hydrogen atom in the form of a proton (H+) to form the CH3CH2CH+ ion. Finally, this ion can lose a methyl group (CH3) to form the CH3CH2+ ion, which can then lose a hydrogen atom (H+) to form the CH3 ion. This CH3 ion can then react with residual oxygen to form the CH3O+ ion with a mass of 31. Choice B has the correct ion (CH3O+) with the correct mass-to-charge ratio (m/z) of 31.

Give the Ion That Corresponds a M/z Ratio of 31