Chromatography

Question 1

Give four potential pigments within the leaves and their colour

Answer 1

Chlorophyll a is a blue green
Chlorophyll b is a yellow green pigment
Carotenoids - yellow or yellow orange pigments

Question 2

Carotenoids are ____________ pigments that absorb wave lengths that the chlorophyll cannot

Answer 2

Accessory pigments

Question 3

Describe the method of chromatography to find photosynthetic pigments

Answer 3

Add a small volume of running solvent to a boiling tube and bung to all the air to become saturated with the solvent
Get a piece of chromatography paper and draw a line in pencil 2cm from the bottom ( not pen is this will be soluble)
Crush the pigments with an extraction solvent e.g. Propanone present
Spot the pigment extract from the mixture onto the origin line of chromatography paper
Place the paper in the boiling tube ensuring the solvent doesnt go above the pigment line

Question 4

Describe the results seen by chromatography and how you can standardise them to compare to other results

Answer 4

Forms a chromatogram
Draw a line to the point where the solvent ran up to - Solvent line
Draw a line at where each pigment ran up to
Calculate an RF value for the data which is: (distance from origin of spot) divided by distance of origin to solvent line)
Compare with data book