Topic 7 Modern Analytical Techniques 1

Question 1

IR spectroscopy

Answer 1

The frequency of IR absorbed by a covalent bond depends on

1. The atoms either side of the bond
2. The position of the bond in the molecule (O-H in the alcohol or carboxylic acid). Watch out for broad and sharp peaks

Question 1

What is mass spectroscopy used for?

Answer 1

It is used to find the MR of the compound

Question 2

What is M/Z?

Answer 2

M/Z is just the mass of a fragment divided by charge. As most have just a +1 charge, so it is just the same as the fragment mass.

Question 3

What do the peaks show?

Answer 3

Peaks shows fragments of the original molecule.
The last peak is the M+1 peak or the molecular ion peak. This is the same as the MR of the molecule. It isn’t fragmented or broken up

Question 4

What is fragmentation?

Answer 4

This is when molecules break up when they are bombarded with high-energy electrons