3.3.16 - Chromatography

Question 1

Outline how chromatography is able to separate a mixture of compounds

Answer 1

1. Solvent is mobile
2. Presence of stationary phase
3. Separation dependent on the relative affinity of compounds to stationary phase

Question 2

Why do different amino acids have different Rf values? (2)

Answer 2

• Amino acids have different polarities
• Therefore have different relative affinities to the stationary and mobile phase

Question 3

How are the positions of amino acid located?

Answer 3

UV light

Question 4

Why does gas chromatography work?

Answer 4

• Different retention times
• Different relative affinity for mobile and stationary phases

Question 5

What determines distance travelled by a spot in TLC?

Answer 5

Relative affnity to the stationary and mobile phase

Question 6

How does polarity of the solvent affect Rf values?

Answer 6

• Polar solvent and a polar molecule
• Results in stronger attraction to the solvent