Separation techniques

Question 1

What is paper chromatpgraphhy?

Answer 1

• often used in food industries
• Ink is smeared onto a piece of filter paper
• paper gets placed in a solvent
• as the paper gets soaked upwards it attracts the various chemicals in the ink with it
• because different chemicals have different rates of attraction to the solvent we can see how much of each chemical is in the product.

Question 2

What is filtration?

Answer 2

• used for separating a liquid from a solid
• a piece of filter paper gets put in a funnel in a flask.
• the mixture is then filtered through the filter paper and you get left with the residue and the filtrate.

Question 3

What is simple distillation?

Answer 3

• used to separate a liquid from a solution

- vapour is collected by condensation

Question 4

what is crystalisation?

Answer 4

separates a soluble solid from a solution

Question 5

how can you calculate the Rf value for each chemical in chromatography?

Answer 5

distance travelled by solute / distance travelled by solvent

Question 6

what is fractional distillation used for?

Answer 6

to separate a mixture of liquids