Chapter 1 Practice Problems – Answers

Q1.1: How many signals appear in the ¹H NMR spectrum of the following compound?

a. 5

b. 6

c. 7

d. 10

Q1.2: How many signals appear in the ¹³C NMR spectrum of the following compound?

a. 9

b. 10

c. 11

d. 14

Q1.3: The signal for which of these hydrogen atoms would be the furthest upfield (have the lowest chemical shift/ppm) in the compound’s ¹H NMR spectrum?

Q1.4: How many triplets appear in the ¹H NMR spectrum of the following molecule?

a. 1

b. 2

c. 3

d. 4

Q1.5: Which of the following compounds has the most signals in its ¹³C NMR spectrum?

Q1.6: Which of the following compounds has a ¹H NMR spectrum with 2 quartets and 2 triplets?

Q1.7: Analysis of a pure sample labelled “nitrotoluene” shows a ¹H NMR spectrum with the following signals:

• a doublet at 7.9 ppm (integrating to 2H)

• a doublet at 7.1 ppm (integrating to 2H)

• a singlet at 2.3 ppm (integrating to 3H)

Based on this, the sample is made of which isomer of nitrotoluene?

a.

b.

c.

d. None of the above.

Q1.8: Consider the following ¹H NMR spectrum with 3 signals:

Which of the following compounds could produce that ¹H NMR spectrum?

Q1.9: For each of the indicated chemically distinct sets of hydrogen atoms predict the multiplicity (shape, coupling pattern) of the signals present in the compound’s ¹H NMR spectrum (e.g. singlet, doublet, triplet, quartet, doublet of triplets, triplet of quartets, etc.).

The multiplicity for the signal for the hydrogen atoms labelled (a) would be

doublet.

The multiplicity for the signal for the hydrogen atom labelled (b) would be

doublet.

The multiplicity for the signal for the hydrogen atoms labelled (c) would be

singlet.

The multiplicity for the signal for the hydrogen atom labelled (d) would be

doublet of doublet of doublets.

The multiplicity for the signal for the hydrogen atom labelled (e) would be

doublet of doublet of quartets.