Proton NMR

Question 1

What do the number of peaks represent in proton NMR?

Answer 1

Number of different proton environments.

Question 2

What does chemical shift represent in proton NMR?

Answer 2

The type of proton environment.

Question 3

What does relative peak area mean in proton NMR?

Answer 3

Relative numbers of proton

Question 4

What does splitting pattern represent?

Answer 4

Number of adjacent protons

Question 5

What does a peak represent?

Answer 5

Number of protons on adjacent atom

Question 6

Definition of labile proton.

Answer 6

-Protons attached to an oxygen or nitrogen are called labile protons because they can rapidly be exchanged with neighbouring molecules.

Question 7

What test is used to identify a labile proton?

Answer 7

Test with D2O (Heavy water), because the H+ has an odd number it shows on the spectrum, once D2O is added, it becomes H2+ hence will become an even peak and will disappear.

Question 8

Describe how you would test a sample in proton NMR.

Answer 8

-Add the sample
-Add TMS
-Add solvent =CDCl3
-Sometimes if needed add D2O