C2.1.6 - Chromatography

Question 1

What is chromatography used for?

Answer 1

Separate mixtures and information to identify substances

Question 2

What are the two phases of chromatography?

Answer 2

Stationary and mobile phase

Question 3

Stationary and mobile phase for paper chromatography

Answer 3

Paper and solvent

Question 4

Stationary and mobile phase for TLC

Answer 4

Silica/alumina powder on glass/plastic and solvent

Question 5

Describe paper chromatography

Answer 5

Separates compounds based on their speed in solvent
- More soluble the substance, further up paper
- Different pigments (solid/coloured) are different substances

Question 6

Describe thin layer chromatography

Answer 6

Works the same way as paper chromatography but different stationary phase

Question 7

Stationary and mobile phase for gas chromatography

Answer 7

Silica/alumina powder in metal column and an unreactive carrier gas

Question 8

Describe gas chromatography

Answer 8

Sample turned into gas, injected into column
Carrier gas (mobile) pushes sample through column
Different entities go through the column at different speeds
- this is dependent on their bond with stationary
Detector sends signal to computer when an entity has gone through, and chromatogram is plotted