Analysis

Question 1

What is the stationary phase in paper chromatography?

Answer 1

The cellulose in the paper.

Question 2

What is the mobile phase in paper chromatography?

Answer 2

The solvent.

Question 3

What is the Rf, what does it tell us and how do we work it out?

Answer 3

The retention factor tells us how easily the sample is moved by the solvent, and is worked out by doing (distance travelled by substance)/(distance travelled by solvent).

Question 4

How is thin layer chromatography (TLC) carried out?

Answer 4

A thin layer of silica gel (SiO₂) or Alumina (Al₂O₃) is coated onto glass, metal or plastic, and the samples are placed onto it.

Question 5

What are the advantages of TLC over paper chromatography?

Answer 5

• It runs faster;
• Smaller amounts of the mixture can be separated;
• The spots usually spread out less;
• The plates are more robust than paper.

Question 6

How do we test for an acyl chloride?

Answer 6

Add water; white misty fumes of HCl will be given off if an acyl chloride is present.

Question 7

How would we test for amines?

Answer 7

Universal indicator, would turn blue.