Which molecular formula is consistent with the following mass spectrum data? M⁺ ^. at m/z= 72, relative height=73.0%
(M+1) ⁺ ^. at m/z= 73, relative height=3.3%

Question

Which molecular formula is consistent with the following mass spectrum data? M⁺ ^. at m/z= 72, relative height=73.0% (M+1)⁺ ^. at m/z= 73, relative height=3.3%

Quizplus · Accepted Answer

The molecular formula C₄H₈O is consistent with the mass spectrum data. The molecular ion peak (M) is seen at m/z = 427, which corresponds to a formula weight of 426 g/mol. This formula has 14 carbon atoms (C14), 18 hydrogen atoms (H18), 1 oxygen atom (O1), and 1 sulfur atom (S1) which corresponds to the observed m/z = 72 peak. The m/z = 73 peak is a result of the presence of one ^13C isotope, giving a relative height of only 3.3%.

Which Molecular Formula Is Consistent with the Following Mass Spectrum