1) The following two spectra were obtained for a pure organic substance, Compound W.


The formula of Compound W that is consistent with the spectra above is
A. CH₂(OH)CH₂CH₂OH
B. CH₃CH₂COOH
C. CH₃COOCH₃
D. CH₃COCH₃

Solution

2) The mass spectrum shown above is for a molecule with the molecular formula C₄H₇Cl. Which species is responsible for the base peak?

Solution

3) A student investigated an organic substance, Compound Y, with the molecular formula C₅H₈O

The infra-red spectrum of Compound Y is shown above. On the spectrum, circle two peaks and identify the bond(s) responsible for each peak.

Solution

4) A sample of Compound Y was further analysed using ¹³C NMR and
¹H NMR. The spectra are shown below.

a) Use the information provided in the ¹³C NMR spectrum to identify the number of different carbon environments for Compound Y.
b) For the signal at 2.3 ppm in the ¹H NMR spectrum, identify what specific information is provided by
• the relative peak area
• peak splitting
d) Draw the structural formula of Compound Y.

Solution