elektra
Platinum Member
do this on video franky so we can ensure you did it all correctly hun,
Equipment and Materials
•A large glass vessel. We have found that a one gallon jar is satisfactory. These can usually be obtained from a restaurant or other food service facility. A small aquarium could also be used.
•A small glass vessel. A beaker or even a drinking glass will be satisfactory, assuming it will fit in the large glass vessel
•A laboratory thermometer
•A heat lamp or equivalent
•Aluminum foil
•Alka-Seltzer tablets
•A balance capable of measuring to the nearest milligram (0.001 gm). If not available, measuring to the nearest 0.01 gm will suffice.
•A watch capable of measuring in seconds
•Graph paper
Procedure
You will treat the air in the large glass vessel as a model of the atmosphere. The vessel will be covered and heated by the "sun" (the heat lamp) until the temperature rises to 15 degrees C above the ambient (surrounding) temperature. The heat lamp is then turned off ("nighttime"), and the air allowed to cool naturally. Temperature readings are taken at definite time intervals and plotted on graph paper. This will show the rate of heat loss from "normal" air. Then, the CO2 concentration of the air will be increased and the experiment repeated. The results will demonstrate the effects of increased CO2 on the rate of heat loss from air. You will then evaluate claims that increasing carbon dioxide will significantly increase the temperature of the atmosphere, and thus lead to climate change, in your lifetime.
PART A: DETERMINING CO2 CONCENTRATIONS
When Alka-Seltzer dissolves in water, a gas is released. This gas is CO2, so Alka-Seltzer tablets serve as a convenient source of this gas. The determination of the amount of CO2 released is an interesting laboratory procedure in itself, and we recommend that high school students be involved in this portion of the experiment .
The first step is to determine the volume of the glass vessel. If a gallon jar is used, use the conversion factor
1 gallon = 3.785 liters.
If some other sized vessel, such as an aquarium, is used its volume can be measured by filling with water using a pint jar as a measuring vessel. The relationship of
1 gallon = 8 pints
can be combined with the conversion factor above to calculate the volume of the vessel in liters. The remainder of this procedure will be described assuming you use a gallon jar.
The next step is to calculate the mass of the air in the vessel. The true density of air is dependent on the amount of moisture present in the air (the humidity) and on the barometric pressure. There are tables and equations which allow a precise computation of the density of air under any set of conditions. These tables can be found in the CRC Handbook of Chemistry and Physics. This calculation is rather complicated; thus for the purposes of this demonstration/experiment, the density of dry air at a pressure of 760 mm of Hg will be assumed. This density is:
0.0012 gm/milliliter.
Since there are 1000 milliliters in 1 liter, the gallon jar contains
3.785 liters X (1000 milliliters/liter) = 3785 milliliters.
The mass of air in the jar can be calculated from the density:
3785 milliliters X (0.0012 gm/milliliter) = 4.542 gm
At this point, assume you wish to determine the rate of heat loss from an atmosphere in which the CO2 concentration has doubled, e.g. which contains 700 ppm CO2. The air in the gallon jar should contain:
4.542 grams X (700/1,000,000) = 0.0032 gm CO2
Thus, we will need to add an additional 0.0016 gm of CO2 to the air in the vessel.
The CO2 will be obtained from the solution of Alka-Seltzer in water. We have performed the following simple test to determine how much CO2 is released from an Alka-Seltzer tablet:
1.A glass vessel containing 75 milliliters of water is weighed to the nearest milligram.
2.An Alka-Seltzer tablet is weighed to the nearest milligram.
3.The tablet is dropped into the water and allowed to dissolve.
4.After 10 minutes, the vessel, water and dissolved Alka-Seltzer is reweighed.
5.The initial weight of the vessel plus water is added to the weight of the Alka-Seltzer tablet (Add values from steps 1 and 2). Then the weight of the vessel, water and dissolved Alka-Seltzer is subtracted from this sum (Subtract value of step 4 from the sum of 1 and 2). The difference is the weight of the CO2 that was released from the Alka-Seltzer.
A typical determination gave the following values:
Weight of vessel plus water 122.37 gm
Weight of Alka-Seltzer tablet 3.35 gm
Total weight 125.72 gm
Weight of vessel, water, and Alka-Seltzer 125.09 gm
Weight of CO2 released 0.63 gm
This information can now be used to determine the amount of Alka-Seltzer necessary to give the 0.0016 gm of CO2 which must be added to the air in the jar to give a concentration of 700 ppm CO2:
(3.25 gm Alka-Seltzer/0.63 gm CO2) X 0.0016 gm CO2
= 0.0083 gm Alka-Seltzer
This is equal to only 0.25% of one Alka-Seltzer tablet (a quarter of 1%); this is a very small amount.
PART B: EFFECT OF CO2 CONCENTRATION ON HEAT LOSS OF AIR
I. Measurement of heat loss for today's "normal" air:
1.Place the small glass vessel filled with water along with the thermometer in the gallon jar and cover the jar loosely with aluminum foil.
2.Heat the air in the jar using the heat lamp "sun" until the temperature is raised by 15 degrees C.
3.Remove the heat lamps to simulate "night". Record the temperature each minute until the temperature returns to ambient.
4.Using graph paper, plot temperature on the Y-axis versus elapsed cooling time on the X-axis.
II. Measurement of heat loss from tomorrow's air containing increased CO2:
1.Crush up an Alka-Seltzer tablet and weigh out the amount needed to increase the CO2 concentration to the desired value. Remember, this will be a very small amount of Alka-Seltzer.
2.Drop the Alka-Seltzer into the water in the small glass vessel inside the large jar. Immediately cover loosely with foil.
3.Allow 10 minutes for all of the CO2 to be released.
4.Repeat steps I-2, I-3, and I-4 above. Plot your results on the same piece of graph paper as above.
Interpretation of your results:
Using the outcome of your experiment, answer the following questions.
1.Which stayed warm longer, the "normal" air, or the air with increased CO2? After cooling for five minutes, what was the difference in their temperatures?
2.Did increasing the CO2 content increase the heat capacity of the air in the jar?
3.Does this experiment indicate that increasing the CO2 content in the atmosphere would cause the climate to get warmer?
4.Explain your answer to question number 3.
Uh, Alka Seltzer? Who's idiotic idea is that, a person who is not a Scientist.
1. If the person who came up with this had even a basic knowledge of Science, like a 1st grade level of Science they would use sodium hydrogen carbonate and acetic acid as the source of CO2.
2. The use of a heat lamp destroys the validity of the experiment. The claim is cosmic radiation causes the C02 in the atmosphere to vibrate thus giving off heat. Cosmic radiation striking/colliding with CO2 is claimed to be sufficient enough to raise the temperature by 1 degree thus this will be easily demonstrated, if true, factual.
3. Unless I missed something, you need two of everything except the source of CO2, you would need a second atmosphere, a "control atmosphere", with less CO2, like 280 ppm or less.
Of course bottles full of gas are about the same as the Global Warming Activists, irrelevant as far as the science goes.
The use of Alka Seltzer by these Scientists is a trick, Alka Seltzer must be dissolved in WATER, with all that bubbling and fizzing going on the contained atmosphere will increase in humidity, H2O. You will thus be measuring the effect of a heat lamp on water.
H2O, the heat lamp will cause the humidity to be higher, longer.
It is a settled science that H2O has the greatest effect on our earth's temperature, that is why Alka Seltzer and Water is used, it increases both.
This experiment does prove two things
1. Idiots are easily fooled.
2. Scientists are liars
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