NMR of hydrogen AQA A2 Chemistry PART 1 of 2 TOPICS

A summary on NMR of Hydrogen with an example being explained.

It is a summary based on the specification by AQA Chemistry specification for this year.

If you have any questions feel free to ask

ENJOY

HideShow resource information
Preview of NMR of hydrogen AQA A2 Chemistry PART 1 of 2 TOPICS

First 297 words of the document:

NMR of hydrogen (AQA A2 Chemistry) PART 1 OF 2 TOPICS
Hydrogen NMR:
NMR of carbon and hydrogen is a form of analytical techniques that can enable scientists to identify
the structures of new compounds. This is achieved because the NMR gives the position of 13 C or 1
H
atoms in a molecule. 13C NMR gives a simpler spectra than 1H NMR.
A symbol is used for chemical shift which is a scale measured in parts per million (ppm). A
standard, Si(CH3)
4 or
tetramethylsilane, is used because:
1. It gives a single peak which is away from all peaks
2. It is inert
3. It has a low boiling so it can be removed from the sample easily
The chemical shift depends on the molecular environment. The y-axis is signal intensity and the x-axis
is /ppm. A peak near to 0.0 (Si(CH3)4) means that the hydrogen(s) on the carbon have high shielding
because it is not near a highly electronegative element like oxygen. The further away the peak is from
the standard peak at 0.0 the lower the shielding where the hydrogen(s) attached to the carbon is
closer to highly electronegative element. This is what we mean by the term molecular environment. A
simple graph with only the axis on illustrates:
On the graph the green peak will be the one plotted more towards the left with the blue peak more towards the right.
Integration values will be to do with each peak having a whole number where it represents how many hydrogens
there were in the environment. E.g. the blue peak will have an integration value of 3 as it has 3 hydrogens for the blue
environment.

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »