Zelda L. Kravitz
The experiments listed below are to be used to aid the students in understanding the concept that matter having mass and volume can neither be created or destroyed, but changed in form. Laboratory reports are essential for each experiment. Descriptions of the materials before and after the experiment should be utilized. All senses should be used except tasting, unless precautions are released.
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1. Burn a candle. Light it and be sure that it is on a piece of metal, as a can cover. Throw match in a metal can or beaker filled with water.
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2. Let an ice cube melt at room temperature on paper towel (precautions removed).
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3. Place a snail on a towel. Bring a lighted natch near, but
NEVER
touching the snail.
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4. Burn a cube of sugar (precautions removed).
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5. Burn a piece of bread (precautions removed).
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6. Burn a wooden splint (take precautions).
Determining Mass
All items are to be weighed before and after the experiment.
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1. Blow up a balloon, weighing it before and after blowing up to the largest size without breaking.
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2. Measure Fe filings. Weigh them, and put them aside until the entire is covered with rust. To hasten this process, a measured amount of water may be added. Leave for a few days.
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3. Fill an empty medicine bottle (plastic-small) bottle one-third full of water. Add one-fourth of one-third water. Add one-fourth tablet of alkaseltzer, and immediately seal the bottle. (Remember that one cubic centimeter or one ml. or water weighs one gram.) (We will neglect the room temperature at this time.)
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a. Using a word equation explain the source of the gas.
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b. What was destroyed? Was anything destroyed?
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c. Use a chemical equation to explain the gas source.
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d. Using limewater, test the gas. You may have to do the experiment again without weighing everything. Blow gently into the straw.
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e. How can you explain the result?
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f. Write an equation, word or chemical, showing what happened.
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g. Label all answers.
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Unmeasured Masses but Chemical Changes
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1. Have a smoker take several puffs of a cigarette, and blow smoke through several sheets of facial tissue.
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a. The teacher should in advance call the Southern Connecticut Lung Association and borrow their equipment for CO gas detection, and the other apparatus, to measure before and after smoking.
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2. Breathe through a straw into limewater, and report the changes.
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3. Using litmus paper, phenothalein, pH paper, separately test: saliva, toothpaste, milk of magnesia, vinegar, baking soda solution, and mouthwash. Record data in a chart you set up yourself.
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a. Rinse mouth with mouthwash and test mouth with indicators again separately.
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b. Is there any change?
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4. Place Iodine solution on a cracker. Chew cracker, and spit into the plastic receptacle. Test with iodine again.
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a. Repeat the chewing of the cracker again, etc. and this time test the substance with Benedicts and Fehling solutions, separately.
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5. Combine baking soda and vinegar. Use 10 grams of baking soda. How many drops of vinegar will cause something to happen?
What is here but we can’t see it?
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1. Using solutions such as NaCl, KCl, Li2Co3, or any other, place a wire loop in the solution and then in the hot part of the bunsen burner flame. Record results in a chart.
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2. Insert the tip of a strip of strip filter paper into black (India Ink), be sure that is is real India Ink. Don’t let the filter paper touch the sides of the container. Use either a 1,000 ml. tube, or a quart size milk carton. Try doing the same thing with tomato juice, red ink, cocoa mixture and black paint. Leave this overnight, and cover the top.
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3. Take a stained piece of cloth. Add bleach to one piece, and peroxide to another. Did anything happen?
Can we time what we do?
Does Temperature Affect the Volume of Matter?
Sometimes we want to find out what happens to matter over a period of time. We need to record the information of a graph. This can be shown by heating a test tube one-half full of anti-freeze, and one test tube of the same amount of water. Inserted in each tube is a Celsius thermometer. Both are heated by bunsen burners. Children doing this experiment should work in groups with each one furnishing a separate report; the information is best collected in a chart, and then transferred to a graph. What happened to the volume of the liquid?
I’ve found that the concept of comparing two or more substances over a period of time can be introduced by using a metronome, which pivots on a shaft, and can be adjusted to various speeds; and comparing it to the movement of a clock; thereby giving the student the concept of a graph being able to compare two or more substances. The student then can be shown how to collect data, place it on a chart and from the chart onto a graph, which he makes himself. Early fall is a good time to do this experiment, as people are starting to think about winterizing their cars.
A homework assignment might be for the child to go home, look in the toilet tank, and try to find out the function of the ball cock in the toilet tank; and also in the interest of conservation, a brick placed in the toilet tank will conserve water. The fact that matter has volume needs to be stressed here.
Doing an experiment at home?
Children at home can be directed to have a box of baking soda near the range or oven. Then they can be asked to figure out why baking soda can be used to put out a flame. The teacher should demonstrate this, as it may be a bit of a mess if all children try it in the class first.
