Question 21
Work in pairs to set up the experiment.
Materials: Coffee filters (round), pair of scissors, clear tape, brightly coloured candy, two metal tablespoons, 500 cm³ beaker of water, toothpicks, glass or clear plastic cup.
1 Prepare the chromatography paper.
a Cut out a small wedge (around 1 cm wide) from the bottom of a coffee filter.
b Roll the coffee filter into a cone shape, with the pointed end at the bottom.
c Secure the cone with a small piece of clear tape.
2 Prepare the candy sample.
a Carefully crush a small piece of candy with a spoon to create a fine powder.
b Add some water to the powder to make a liquid dye.
3 Set up the chromatography chamber by filling the clear cup with water, about 1 cm from the bottom of the cup.
4 Spot the sample.
a Dip a toothpick into your candy sample.
b Carefully dab a small dot of the sample near the pointed tip of your coffee filter cone, about 1 cm from the bottom.
c Allow the spot to dry completely. This may take a few minutes.
5 Run the chromatography.
a Place the coffee filter cone with the sample dot upside down into the clear cup.
b Make sure only the tip of the cone touches the water in the cup. The dot should be just above the water level.
6 Observe the separation.
a Watch the water slowly travel up the coffee filter cone. As the water moves, the colours in your candy sample will start to separate and travel at different speeds.
b In the space below, draw the chromatogram you observe.
Materials: Coffee filters (round), pair of scissors, clear tape, brightly coloured candy, two metal tablespoons, 500 cm³ beaker of water, toothpicks, glass or clear plastic cup.
1 Prepare the chromatography paper.
a Cut out a small wedge (around 1 cm wide) from the bottom of a coffee filter.
b Roll the coffee filter into a cone shape, with the pointed end at the bottom.
c Secure the cone with a small piece of clear tape.
2 Prepare the candy sample.
a Carefully crush a small piece of candy with a spoon to create a fine powder.
b Add some water to the powder to make a liquid dye.
3 Set up the chromatography chamber by filling the clear cup with water, about 1 cm from the bottom of the cup.
4 Spot the sample.
a Dip a toothpick into your candy sample.
b Carefully dab a small dot of the sample near the pointed tip of your coffee filter cone, about 1 cm from the bottom.
c Allow the spot to dry completely. This may take a few minutes.
5 Run the chromatography.
a Place the coffee filter cone with the sample dot upside down into the clear cup.
b Make sure only the tip of the cone touches the water in the cup. The dot should be just above the water level.
6 Observe the separation.
a Watch the water slowly travel up the coffee filter cone. As the water moves, the colours in your candy sample will start to separate and travel at different speeds.
b In the space below, draw the chromatogram you observe.
