Purification And Checking Purity

Question 1

What are the methods used to check if a substance is pure?

Answer 1

paper or thin - layer chromatography

Question 2

What advantages does thin-layer chromatography have over paper chromatography?

Answer 2

• Quicker
• More sensitive so a smaller sample can be used
• Larger range of stationary phases and solvents to choose from

Question 3

How do you separate insoluble and soluble substances?

Answer 3

dissolving followed by filtration

Question 4

How do you separate a solute dissolved in a solvent?

Answer 4

• Crystallisation to obtain the solute
• Simple distillation to obtain the solvent

Question 5

How do you separate 2 or more subsances in the liquid state?

Answer 5

fractional distillation

Question 6

How do you separate coloured soluble substances?

Answer 6

paper chromatography or thin-layer chromatography