C2 Chemistry - paper and gas chromatography

Question 1

what is paper chromatography?

Answer 1

used to separate mixtures of coloured compounds

Question 2

what are the mixtures suitable for chromatography?

Answer 2

inks, dyes and colouring agents in foods

Question 3

what happens in paper chromatography?

Answer 3

spot of mixture on paper
paper placed in solvent 
solvent soaks up the paper
carries mixture with it 
different components of the mixture move at different rates

Question 4

what are RF values?

Answer 4

separated components of the mixtures can be identified by calculating the RF values

Question 5

how do you calculate the RF values?

Answer 5

distance moved by the components divided distance moved by the solvent

Question 6

what is gas chromatography?

Answer 6

allows a mixture of compounds to be separated

Question 7

what is the tube used in GC called?

Answer 7

a column

Question 8

explain the process of GC

5 steps

Answer 8

1. sample dissolved in solution
2. put in one end of the column
3. unreactive gas carries sample through column
4. different substances travel at different times, becoming separated
5. separated substances leave at different times, and are detected by a detector

Question 9

what is retention time?

Answer 9

the time taken for substance to pass through column