Unit 2- Assignment C
Chromatography:
Chromatography of leaves: (paper)
Equipment:
- Pestle and mortar
- Chromatography paper
- Teat pipette
- 100cm3 beaker
- Small capillary tube
- Sand
- Leaves and scissors
- Propanone
Preparation of plant solution:
When preparing the solution it was important to ensure that the concentration
was high, but the volume was low, which means that the pigment was not too
diluted. If solution was too dilute, the separation would have been very difficult
to see.
To make the plant solution, the leaves were firstly cut up into small pieces, which
made the leaves easier to crush up. Sand was then added to help break down
the leaves, and a small amount of propanone. The leaves were then crushed
using a pestle and mortar to form a small amount of concentrated pigment
solution.
Method for paper chromatography:
Using a fine glass tube, the liquid from the leaf extract was placed onto the
centre of the line and then the spot was left to dry. This was repeated to build up
a very concentrated small spot of the chromatography paper.
Next, a small amount of propanone was put within a beaker and then the paper
was hung so that it dipped into the propanone. It was important to ensure that
the level of propanone was below the spot. The chromatography paper was then
left until the propanone had soaked in near the top. With a pencil, the height of
the proponone was marked, then the chromatography paper was left to dry out.
RF values: (Green)
Distance moved by spot= 2 cm
Distance moved by the solvent= 6.7cm
Rf = 2/6.7= 0.3
RF values: (Yellow)
Distance moved by spot= 2.2cm
Distance moved by the solvent= 6.7cm
Rf = 2.2/6.7= 0.33
Chromatography:
Chromatography of leaves: (paper)
Equipment:
- Pestle and mortar
- Chromatography paper
- Teat pipette
- 100cm3 beaker
- Small capillary tube
- Sand
- Leaves and scissors
- Propanone
Preparation of plant solution:
When preparing the solution it was important to ensure that the concentration
was high, but the volume was low, which means that the pigment was not too
diluted. If solution was too dilute, the separation would have been very difficult
to see.
To make the plant solution, the leaves were firstly cut up into small pieces, which
made the leaves easier to crush up. Sand was then added to help break down
the leaves, and a small amount of propanone. The leaves were then crushed
using a pestle and mortar to form a small amount of concentrated pigment
solution.
Method for paper chromatography:
Using a fine glass tube, the liquid from the leaf extract was placed onto the
centre of the line and then the spot was left to dry. This was repeated to build up
a very concentrated small spot of the chromatography paper.
Next, a small amount of propanone was put within a beaker and then the paper
was hung so that it dipped into the propanone. It was important to ensure that
the level of propanone was below the spot. The chromatography paper was then
left until the propanone had soaked in near the top. With a pencil, the height of
the proponone was marked, then the chromatography paper was left to dry out.
RF values: (Green)
Distance moved by spot= 2 cm
Distance moved by the solvent= 6.7cm
Rf = 2/6.7= 0.3
RF values: (Yellow)
Distance moved by spot= 2.2cm
Distance moved by the solvent= 6.7cm
Rf = 2.2/6.7= 0.33
