Lawrie Ryan and Roger Norris Solutions for Chapter: Atoms, Molecules and Stoichiometry, Exercise 5: Question

Look at the mass spectrum of ethanol, ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$. A structural isomer of ethanol is methoxy methane, an ether with the formula ${\mathrm{CH}}_3{\mathrm{OCH}}_3$.

Predict the mass-to-charge ratio of a fragment that would appear on the mass spectrum of methoxy methane but does not appear on methanol's mass spectrum.

Look at the mass spectrum of ethanol, ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$. A structural isomer of ethanol is methoxy methane, an ether with the formula ${\mathrm{CH}}_3{\mathrm{OCH}}_3$.

Predict and give the name of the fragment that would appear on the mass spectrum of methoxy methane but does not appear on methanol's mass spectrum.

Look at the mass spectrum of ethanoic acid.

Identify the fragment with mass-to-charge ratio of $15$.

A hydrocarbon has molecular ion peak at mass-to-charge ratio of $84$ (relative abundance $62\%$) and an $\left[\mathrm{M}+1\right]$ peak with a relative abundance of $4.1\%$.

How many carbon atoms are in the hydrocarbon?

List the ions responsible for the $\mathrm{M}$, $\left[\mathrm{M}+2\right]$ and $\left[\mathrm{M}+4\right]$ peaks in the mass spectrum of dibromomethane.

What would be the mass-to-charge ratio and relative abundances of the major peaks with the highest charge-to mass ratios in the mass spectrum of chloroethane?

How many peaks would you see beyond the molecular ion peak in $1,1$-dibromoethane? What would be their mass-to-charge rations and abundances relative to the molecular ion? (Ignore peaks due to ${}^{13}\mathrm{C}$).