1. Consider the following statements.
I. HPLC is a qualitative process.
II. HPLC is a quantitative process.
III. Triplets give information about molecule structure.
Which of the above statements apply to high-performance liquid chromatography (HPLC)?
A. I only
B. II only
C. I and II only
D. I, II and III

2. Consider the following molecule.

How many peaks will be observed in a 13C NMR spectrum of this molecule?
A. 5
B. 6
C. 7
D. 8

Solution

3. Which one of the following statements about mass spectrometry is always correct?
A. The relative molecular mass of a molecule is determined from the base peak.
B. The peaks in a mass spectrum are caused by the presence of different isotopes.
C. The base peak is formed when an uncharged species is removed from the molecule.
D. The height of each peak in the mass spectrum is measured relative to the height of the base peak.

Solution

4. Molecule V contains only carbon atoms, hydrogen atoms and one oxygen atom.

a. The mass spectrum of molecule V is shown below.

i. State the molecular formula of molecule V. Justify your answer by using the information in the mass spectrum.

ii. State why there is a small peak at m/z = 87.

Solution

b. The ¹H NMR spectrum of Molecule V is shown below.

State what information the doublet at 1.1 ppm provides about the structure of the molecule.

Solution

c. The ¹³C NMR spectrum of molecule V is shown below.

In the space below, draw a structural formula of molecule V that is consistent with the information provided in parts a.–c .

Solution

The infrared (IR) spectrum of molecule V is shown below.

d. Explain why different frequencies of infrared radiation can be absorbed by the same molecule as shown in the spectrum above. 3 marks

Solution