Paper pencil line draw leaf solvent travelled required

Text	Required Practical 7: Chromatography and pigments from leaves 1. Draw a straight line in pencil approximately 1cm above the bottom of the filter paper being used. Do not use a pen as the ink will obscure the results. 2. Cut a section of leaf and place it in a mortar. Add 20 drops of acetone and use the pestle to grind up the leaf sample and release the pigments. 3. Use a capillary tube to extract some of the pigment and blot it onto the centre of the pencil line you have drawn. 4. Suspend the paper in the solvent so that the level of the liquid does not lie above the pencil line and leave the paper until the solvent has run up the paper to near the top. 5. Remove the paper from the solvent and draw a pencil line marking where the solvent moved up to. The pigment should have separated out and there should be different spots on the paper at different heights above the pencil line. 6. Calculate the Rf value for each spot (distance travelled by solute/distance travelled by solvent). Always measure to the centre of each spot.

Text

Required Practical 7: Chromatography and pigments from leaves

1. Draw a straight line in pencil approximately 1cm above the bottom of the filter paper being used. Do not use a pen as the ink will obscure the results.

2. Cut a section of leaf and place it in a mortar. Add 20 drops of acetone and use the pestle to grind up the leaf sample and release the pigments.

3. Use a capillary tube to extract some of the pigment and blot it onto the centre of the pencil line you have drawn.

4. Suspend the paper in the solvent so that the level of the liquid does not lie above the pencil line and leave the paper until the solvent has run up the paper to near the top.

5. Remove the paper from the solvent and draw a pencil line marking where the solvent moved up to. The pigment should have separated out and there should be different spots on the paper at different heights above the pencil line.

6. Calculate the Rf value for each spot (distance travelled by solute/distance travelled by solvent). Always measure to the centre of each spot.

Learn with these flashcards. Click next, previous, or up to navigate to more flashcards for this subject.