1) a)How many different proton types are found in ethane?

b) How many sets of peaks are found in the proton NMR spectrum of ethane?

c) How many peaks does each set have?

Solution

2) Consider the ¹H NMR of 2-bromobutane, shown on the right.

Given the structure of the molecule determine the protons that give rise to each set of peaks. CH₃CHBrCH₂CH₃

Solution

3) a) How many different proton types are found in pentane?

b) How many sets of peaks are found in the proton NMR spectrum of pentane?

c) How many peaks does each set have?

Solution

4) a) The hydrogen atoms in red are represented by the set of peaks labeled A B C

b) The hydrogen atoms in blue are represented by the set of peaks labeled

c) The hydrogen atoms in black are represented by the set of peaks labeled A B C

d) What is the expected ratio of the areas under the sets of peaks A:B:C 4:6:2 6:4:2 4:6:6 2:1:3

5) a) How many different proton types are found in this molecule? 2 1 3 15

b) The set of peaks labeled"A" corresponds to which coloured group of atoms? Blue Red Black

c) The set of peaks labeled"B" corresponds to which coloured group of atoms? Blue Red Black

Solution

6) Which one of the four molecules can produce the proton spectrum shown? The relative areas of each set of peaks is shown on the top.

a) CH₃CH₂CHOHCH₃

b) CH₃CH₂CH₂CH₂OH

c) CH₃CH₂OCH₂CH₃

d) CH₃CH₂CH₂CH₂CH₂OH

Give the number of sets of peaks for each structural formula given below. Give the number of spikes for the hydrogen represented with the *.

e) CH₃CH*₂CHOHCH₃ The number of sets of spikes is 1 2 3 4 5 6 7 8 Hydrogen * has 1 2 3 4 5 6 7 8 spikes in the set

f) CH₃CH₂CH*₂CH₂OH The number of sets of spikes is 1 2 3 4 5 6 7 8 Hydrogen * has 1 2 3 4 5 6 7 8 spikes in the set

g) CH₃CH₂OCH*₂CH₃ The number of sets of spikes is 1 2 3 4 5 6 7 8 Hydrogen * has 1 2 3 4 5 6 7 8 spikes in the set

h) CH*₂CHCH₂CH₂OH The number of sets of spikes is 1 2 3 4 5 6 7 8 Hydrogen * has 1 2 3 4 5 6 7 8 spikes in the set

Solution

7) a) How many different proton types are found in pentane? 8 4 2 3

b) How many sets of peaks are found in the proton NMR spectrum of pentane? 8 4 2 3

c) How many peaks does each set have?

8) Which one of the following molecules will produce the proton NMR spectrum shown on the right?
CH₃CH₂CHOHCH₃ or CH₃CH₂CH₂CH₂OH

Solution

10) Which molecule is most likely represented by the H NMR spectrum shown on the right?

Solution

11) Which molecule is most likely represented by the H NMR spectrum shown on the right?

Solution

12) Which molecule is most likely represented by the H NMR spectrum shown on the right?

Solution

13) Draw the proton NMR spectrum for the molecule shown on the right. The less the nuclear shielding the greater the chemical shift. Solution

Consider the HNMR spectra of the following compounds and decide on their molecular structure.

C₃H₇OCl

C₄H₈O₂

C₄H₇O₂Br