Topic 16: Organic Analysis

Question 1

M peak

Answer 1

Molecular ion peak, Mr of the molecular ion

Question 2

m/z

Answer 2

Mass/ charge
Usually z is 1so just Mr

Question 3

Why ions for mass spec?

Answer 3

SAMPLE IS IONISED AT THE START REMEMBER!

Question 4

IR spectrum

Answer 4

A technique used to identify the functional groups in a molecule

Question 5

IR Spectrum process

Answer 5

• A beam of infrared containing a spread of frequencies is passed through a sample
• The radiation that emerges is missing the frequencies that correspond to the types of bonds found in the sample
• The instrument plots a graph of the intensities of the radiation emerging from the sample, called the transmittance, against the frequency of radiation.
• The frequency is expressed as a wavenumber.

Question 6

Stronger bonds vibrate

Answer 6

Faster

Question 7

Heavier atoms make the bond vibrate

Answer 7

Slower

Question 8

Fingerprint region

Answer 8

From 1500-500, contains a very complicated series of absorptions, unique to the molecule so can be used to distinguish between different molecules.