Question 62
Think like a scientist: Is the green colour in plant leaves pure?
You will need:
- fresh plant material such as spinach
- pestle and mortar
- ethanol
- pipette
- chromatography paper
- beaker
- pencil
- glass rod or spill
Safety
When using ethanol, make sure you are in a well-ventilated room and there are no heat sources close to you.
Method
1. Add a handful of spinach and a few drops of ethanol into the mortar. Use the pestle to crush the spinach and ethanol together. Let it stand for about 10 minutes to leave time for the green pigment to dissolve in the ethanol.
2. Prepare the chromatography paper with a pencil line and a cross, about 1 cm from the end.
3. Use a pipette to load some of the green liquid from the mortar onto the cross. Allow the spot to dry before adding more of the liquid.
4. Place the chromatography paper over a glass rod or pencil. Hang it in a beaker containing some ethanol, so that the pencil line is just above the ethanol.
5. Watch carefully and remove the chromatography paper before the ethanol reaches the top of the paper. The point that the solvent reaches is called the solvent front.
Allow the chromatogram to dry and then stick it in your book.
Is the green pigment in plants pure? What is your evidence for this?
You will need:
- fresh plant material such as spinach
- pestle and mortar
- ethanol
- pipette
- chromatography paper
- beaker
- pencil
- glass rod or spill
Safety
When using ethanol, make sure you are in a well-ventilated room and there are no heat sources close to you.
Method
1. Add a handful of spinach and a few drops of ethanol into the mortar. Use the pestle to crush the spinach and ethanol together. Let it stand for about 10 minutes to leave time for the green pigment to dissolve in the ethanol.
2. Prepare the chromatography paper with a pencil line and a cross, about 1 cm from the end.
3. Use a pipette to load some of the green liquid from the mortar onto the cross. Allow the spot to dry before adding more of the liquid.
4. Place the chromatography paper over a glass rod or pencil. Hang it in a beaker containing some ethanol, so that the pencil line is just above the ethanol.
5. Watch carefully and remove the chromatography paper before the ethanol reaches the top of the paper. The point that the solvent reaches is called the solvent front.
Allow the chromatogram to dry and then stick it in your book.
Is the green pigment in plants pure? What is your evidence for this?
