Topic 21

Question 1

Predict the chemical shifts and integration for each signal in the 1H NMR spectrum for ethanol using section 27 of the data booklet.

Answer 1

R–OH:

1.0–6.0 «ppm» AND 1 H

R–O–CH2–:

3.3–3.7 «ppm» AND 2 H

–CH3:

0.9–1.0 «ppm» AND 3 H

Question 2

Why is TMS used as the standard for HNMR?

Answer 2

• It is non toxic and unreactive
• It is volatile so has a low boiling point in order to be removed from the sample
• All its protons are in the same chemical environment so it gives a strong single peak