Proton NMR

Question 1

What does each peak represent?

Answer 1

A different hydrogen environment

Question 2

What is the integration trace?

Answer 2

The number above the peak which tells us the number of hydrogens in each environment

Question 3

Hydrogens closer to oxygen and nitrogen…

Answer 3

Have a higher chemical shift value due to being closer to a more electronegative element

Question 4

Why is CCl4 a good solvent?

Answer 4

Because it contains no hydrogen so will not cause any peaks due to no presence of hydrogen environments

Question 5

Detecting OH and NH…

Answer 5

Use D2O solvent which replaces the hydrogen in these groups and make a new spectrum: no peaks appear on new spectrum so we know what peak is responsible for OH and NH

Question 6

Does deuterium produce peaks as it is H?

Answer 6

No

Question 7

Splitting patterns of a peak

Answer 7

The splitting of a peak shows the number of hydrogens bonded to the neighbouring carbon (-1)

Question 8

n+1 rule

Answer 8

For a given peak, it’s splitting depends on the number of hydrogen bonded to the nextdoor carbon PLUS 1

Question 9

Hydrogens in the same environment on different carbons when it comes to splitting….

Answer 9

Are equivalent so will not cause any effect on splitting

Question 10

What is the integrator trace?

Answer 10

A measure of the difference in height of different peaks, the ratio in height is proportional to the number of hydrogens in each hydrogen environment

Question 11

Low resolution hydrogen NMR

Answer 11

Does not show splitting
So each peak is merged into one: area under shows number of hydrogen in this environment