Chapter 13, Problem 13.38P

A low-resolution mass spectrum of the neurotransmitter dopamine gave a molecular ion at $m\text{/}z=153$.

Two possible molecular formulas for this molecular ion are ${\text{C}}_{\text{8}}{\text{H}}_{\text{11}}{\text{NO}}_{\text{2}}{\text{ and C}}_{\text{7}}{\text{H}}_{\text{11}}{\text{N}}_{\text{3}}\text{O}$. A high-

resolution mass spectrum provided an exact mass at $153.0680$. Which of the possible molecular

formulas is the correct one?