Synthesis and Analysis

Question 1

Describe the main features of thin layer chromatography

Answer 1

Absorbent material on a plastic backing plate

As solution rises up, mixture will separate into its individual components, Rf values are then calculated

Question 2

Describe the main features of gas liquid chromatography

Answer 2

A gaseous mixture is passed through liquid particles supported on an unreactive solid
The temperature can be adjusted for effective separation
The compounds are identified using their retention times (time to emerge from the column)

Question 3

Describe the main features of high performance liquid chromatography

Answer 3

Mixture is injected into a mobile liquid phase that is under pressure
This carries the mixture through the instrument enabling separation
Compounds are identified using retention times

Question 4

Steps for recrystalisation

Answer 4

1. Dissolve in a minimum volume of hot solvent
2. Filter hot
3. Allow to cool
4. Re-filter
5. Dry the crystalline product