Question

Determine the molecular ion peak for chlorobromomethane. Using the attached isotope table also determine the molecular isotope peaks and their relative intensities.

Answer 1

Chlorobromomethane is CH₂BrCl

Molecular ion peak: The simple removal of an electron from a molecule yields an ion, which is known as molecular ion peak (M+) The value of m/e at which molecular ion appearson the mass spectrum gives the molecular weight of the original molecule.

M⁺ of CH₂BrCl will appear at m/e = 129.3 and since molecular weight is 129.3 g/mol.

For BrCl, isotope peaks will appear at M+2 and M+4

M+2 will have relative intensity 130.0

M+4 will have relative intensity 31.9