Chromotography

Question 1

What does it do

Answer 1

Separates mixture based on relative solubility of the sample

Question 2

RF calculations ( retention factor )

Answer 2

Distance moved by sample / distance moved by solvent from baseline

Values always between 0 ( insoluble ) and 1 ( completely soluble in mobile phase )

Question 3

What apparatus do you need
RP

Answer 3

Beaker
Chromatography paper
Four known food colourings labelled A-D
An unknown mixture of food colourings labelled U
Ruler
Pencil
Capillary tube (5)
Paper clip
Wooden spill

Question 4

Method

Answer 4

1) Draw a horizontal pencil line 2cm from the bottom of the short edge of the chromatography paper

2) mark five spots in even intervals across the origin line

3) put each colouring A-D on a pencil spot. Use a different capillary tube each time. On the fifth spot put unknown mixture marker U. Label each spot in pencil

4) pour water into the beaker to a depth of 1cm

5) clip the end furthest away from spots to a wooden spill

6) carefully rest the wooden spill on the top edge of beaker and the bottom edge of paper should dip into the water solvent.