The MEALWORM experiment
Apparatus:
1 Tweezers
3 Test tube
1 Measuring cylinder [Smaller version for measuring small amount of liquid]
1 Test tube rack
3 Stoppers
3 Wire Gauze [Made into 'mini bowl' shape]
3 Copper Wires [Each about 10cm, to be attached to 'bowls' for convenience]
Materials:
70 Mealworms [Keep them in a container with holes for respiration and with bread for food]
5 Beetles
1 Bottle of Hydrogen Carbonate Indicator
1 Stopwatch
Steps:
1. Using the measuring cylinder, measure around 5ml of the Hydrogen Carbonate Indicator by gently pressing the bottle for the solution to drip out.
2. Pour the solution in the measuring cylinder into the test tube and immediately cover it with a stopper after the 'mini bowl' wire mesh have been placed inside and then place it at the test tube rack.
3. Repeat steps 1-2 for the next 2 test tubes. Once that is done, proceed to step 4.
4. Open a test tube and using the tweezers,slowly retrieving the mealworms inside the container,put 40 mealworms into the test tube. Do not tilt or shake the test tube as the solution might touch the wire mesh bowl and kill the mealworms in it. After all the mealworms are in, push in the stopper and start timing for 20 minutes and label it test tube 1.
5. Repeat step 4 but this time with only 20 mealworms and label it test tube 2.
6. The final test tube will be for us humans to breathe carbon dioxide into it. Place the last test tube near the mouth and exhale. After 10 minutes, push the stopper back in.
7. Make your observations.
Results:
Test tube 1 [40worms] >>> The Hydrogen Carbonate Indicator turns from purple to yellowish-red.
Test tube 2 [20worms] >>> The Hydrogen Carbonate Indicator turns from purple to distant yellowish-red.
Test tube 3 [Breathe] >>> The Hydrogen Carbonate Indicator turns from purple to distant yellowish-red.
Experimental error:
1. The timing for the mealworms to respire was too short to observe very obvious changes in the solution.
2. Another experimental error would be that some of us kept the test tube open while placing in the mealworms so, the solution might have turned yellowish-red due to us exhaling, not the mealworm.
3. We used 39mealworms and 1 beetle in Test tube 2. It makes it unfair as a beatle might have exhale more carbon dioxide compared to a mealworm maybe due to different respiratory needs or system.
BUSSTMEE> Did you know that limewater(saturated calcium hydroxide solution)(different from lime juice) can replace the Hydrogen Carbonate Indicator in this experiment but it would take a longer duration for the experiment to be carried out.
The Cobalt Chloride paper experiment
Materials:
Strips of Cobalt Chloride Paper [Required amount]
Ourselves
Procedure:
1. After the Cobalt Chloride paper is taken out from its container, place it near your mouth and exhale on to it. Remember not to hold it too close to prevent chloride poisoning.
Expected Results:
The cobalt chloride paper turned from blue to slightly pale pink.
Observed Results:
The cobalt chloride paper that was pale pink remained the same colour.
Experimental error:
1. The cobalt chloride paper was stored in a container that wasn't air tight.Thus, the water vapour in the air might have already change the paper from blue to pink.Therefore so we don't see a change.
Conclusion:
Gases we exhale contains water vapour.
BUSTME> Here's an experiment using COBALT CHLORIDE PAPER to determine which side of the leaf losses more water?
Which side of the leaf loses more water experiment
Materials:
4 Stripes of cobalt chloride paper [It MUST be blue]
Adhesive tape [aka, Scotch Tape, must be Transparent]
1 Potted Plant with leaves
1 Stopwatch
Procedure:
1. Tape a strip of cobalt chloride paper to each side of 2 leaves.
2. Use one leaf in the sunlight and one leaf in the shade.
3. Remember leaves need to remain attached to the plant!
4. Every 60 seconds for 10 minutes, record the color of the paper. (Is it still blue, part pink, all pink, etc.?)
5. Record your data in a table such as found below.
6. When allowed to sit in a dry location, the cobalt chloride strips will return to their original state and can be reused.
And this is what you should see:
Ta-dah! The underside part of the leaf losses more water.
Posted by Glenn edited by wilber
No comments:
Post a Comment