Analyze Candy Using Chromatography

Analyze Candy Using Chromatography

Step 1 of 9:

Here's the Materials You'll Need:

At least two kinds of candy-coated sweets (like M&Ms, Reese’s Pieces, Skittles) in the same color(brown works best)
Coffee filters cut into 1” x 3” strips
Toothpicks
Small glasses
Water
Pen

Key Terms Defined

Chromatography

A method for analyzing complex mixtures by separating them into the chemicals from which they are made.

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Step 2 of 9:

An adult should complete steps 2 through 4 without letting the children see. Dampen an M&M and make a smudge on a coffee filter strip about a third of the way up. This is the candy evidence that was found at the crime scene.

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Step 3 of 9:

Poke a toothpick through the top of the crime scene filter paper. Rest the toothpick on the edge of an empty glass (or hold it) so the filter paper hangs down inside.

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Step 4 of 9:

Add enough water to the cup so that it touches the bottom of the crime scene filter paper but does NOT touch the candy smudge. Allow the water to rise up the filter paper, which causes the candy smudge to spread out. This will take a few minutes. Remove the crime scene filter paper from the water and allow it to dry.

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Step 5 of 9:

The children can complete the following steps. Write “A” at the top of one of the unused filter papers and “B” at the top of another unused filter paper.

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Step 6 of 9:

Dampen an M&M and make a smudge on the “A” coffee filter strip about a third of the way up. Dampen the other candy (Reese’s Pieces, Skittles, etc.) and make a smudge on the “B” coffee filter strip about a third of the way up.

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Step 7 of 9:

Poke a toothpick through the top of the filter paper. Rest the toothpick on the edge of an empty glass so the filter paper hangs down inside. Repeat with the other filter paper. Add enough water to each cup so that it touches the bottom of the filter paper but does NOT touch the candy smudge. Allow the water to rise up the filter paper, which causes the candy smudge to spread out. This will take a few minutes.

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Step 8 of 9:

Remove the filter papers from the water and allow them to dry. Compare the “A” and “B” filter papers to the crime scene filter paper. Which type of candy was left at the crime scene?

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Step 9 of 9:

The dyes used to make colored candy can be made up of several colors. These dyes are composed of different compounds that separate during chromatography. The water rising up the filter paper caused the compounds in the candy to spread out in a spectrum.
Try this – Try this activity with different types of candy, or with candy of different colors. How are the results different?
Source:Museum of Science and Industry, Chicago

What happens when you burn a candle at both ends?

What happens when you burn a candle at both ends?

Materials needed

• Candle
• Match
• Toothpicks
• Water glasses

Procedure

1. Prepare a candle so the wick may be lighted at both ends.

2. Insert round toothpicks into the candle and balance it on the water glasses as shown in the illustration. It doesn't have to balance perfectly.

3. Predict what will happen if you light body ends of the candle.

4. Light both ends of the candle. Observe for several minutes. What happened?

5. Think about it. And explain what happened the best you can. Share your ideas with others in your group.

Teacher information

Caution: activities with fire or heat should be done only under close adult supervision or as a teacher demonstration.

                When the candle is lighted at both ends, the end tilting downward will burn wax away more rapidly and become lighter. When it tilts up, the other end will be down, and it will burn wax away more rapidly. As this process continues to reserve, the candle will rock back and forth, often quite vigorously.

What happens to gases as they are heated and cooled?

What happens to gases as they are heated and cooled?

Materials needed

• Narrow necked jar with one whole stopper
• Balloon stick (available from cart or party supply stores)
• water

Procedure

1. Put a small amount of water in the bottom of the jar.
2. Insert the plastic tube through the stopper
3. Place the stopper in the jar. The lower and of the tube must be in the water.
4. Notice the water level in the tube.
5. Place the jar in a window in direct sunlight.
6. Check the water level in the tube every three or four minutes for at least one half hour.
7. What happened to the water level as the air warmed in the sunlight? Why?
8. Remove the jar from the sunlight and place it in cool place.
9. Again check the water level in the tube every few minutes.
10. What happened to the water level as the air cooled? Why?
11. What can you say about the effect of temperature change on gases?

For the problems solvers: 

blow up a balloon and measure the distance around it with a string. Mark the string to show the length required to reach around the balloon. Place the balloon over heat vent in front of a heater for a few minutes. Use the same string to measure the distance around the balloon again. Is there a difference? Can you explain why?
Learn what you can about hot balloons. Why do they rise into the air? Why do they come down again? Do balloon pilots usually fly their ships in the cool air of morning or in the heat of the afternoon? Why?

Teacher Information

This activity is very similar to activity 2.11, but this time the changes in water level in the tube are caused by expansion and contraction of air within the jar instead of expansion and contraction of liquid. As the air in the jar warms in the sunlight, it will expand, forcing water up the tube and very likely spilling it out the top of the tube, demonstrating that as the temperature of gas increases, the gas expands. At the air cools, it will contract and the level of the water in the tube will drop.
If food coloring is available, add a few drops to the water to make the water level in the tube more visible. This is a type of thermometer.

What happens to liquids as they are heated and cooled?

What happens to liquids as they are heated and cooled?

Materials needed

• · Narrow-necked jar with a one whole rubber stopper.
• Balloon stick (available from craft or party supply stores)
• · Marker, rubber band, or masking tape
• · Water

Procedure

1. Fill the jar completely with cold water.
2. Insert the plastic tubing through the rubber stopper.
3. Place the stopper in the jar. As you press the stopper into place, three should be no air space beneath the stopper, and water should be force part way (not more than half way) up the tube above the stopper.
4. Mark the tube at the water level with a marker, or by a putting a rubber band or tape around it.
5. Place the jar in a window in direct sunlight.
6. Check the water level in the tube every few minutes for at least two hours.
7. What happened to the water level as the water warmed in the sunlight?
8. Remove the jar from the sunlight and place it in a cool place.
9. Again check the water level in the tube every few minutes.
10. What happened to the water level as the water cooled?
11. What can you say about the effect of temperature change on liquids?

For problems solvers:

if a motorist goes to the filling station on a hot day and fills the fuel tank clear to the brim, then sparks the vehicle in the sun for two or three hours, sometimes tank will overflow and spill fuel onto the ground. Think about the above activity and see if you can explain why the tank overflows. The manager at your local filling station would probably be glad to discuss to it with you if you have any questions or if you‘d just like to find out if your explanation is correct. Any experienced truck driver could also discuss it with you.

Teacher information

The ideal tube for this activity is a balloon stick, available at party supply outlets.
As the jar of water warms in the sunlight, the water will expand and the water level will expand and the water level will rise in the tube, demonstrating that as the temperature of liquid increases the liquid expands.
As the water cools it will contract, and the level of the water in the tube will drop.
If food coloring is available, have students add a few drops to the drops to the water. This makes the water level in the tube easier to see, and the change is more evident.
This device can become a thermometer if you have students attach a card to the tube and mark the card at different temperatures, by taking temperature readings from a commercial thermometer. Water evaporation in the tube will eventually destroy the accuracy of it as a thermometer and it will need to be re calibrated.
Filling stations store gasoline in large tanks beneath the ground. Thus, the fuel is cool. if a motorist fills the tank, then parks the vehicle in the sun for a time, the fuel will expand from the heat and will sometimes overflow onto the ground.