I set up this experiment by using only three insulators instead of the four that we were told to use. I did this because of a lack of supplies, primarily beakers, and because of the need for a control in this experiment. I used cheesecloth, a hand towel, and aluminum foil for my insulators. The water that I used had an initial temperature of 25°C, meaning that this is the temperature that the water could possibly cool down to after being heated, if given enough time to do so. I heated the water to 72°C and put 200mL of water into four separate beakers (instead of mugs). I put each insulator tightly on separate beakers, put a rubber band around it, and waited 30 minutes. After 30 minutes, the control beaker’s temperature cooled to 39°C, the cheesecloth to 41°C, the hand cloth to 47°C, and the foil to 51°C. Based on just this information alone, I could adequately conclude that the aluminum foil served as the best insulator.
Additionally, however, I noticed that the beaker that had the foil over it also produced the most condensation. Condensation decreased as the difference between initial and end temperatures increased. This was due to the following reasons, as the water cooled, thus meaning that heat energy was released, condensation occurred. But, as this cooling process continued, condensation exceeded the rate of evaporation, thus reverting water molecules that were in the gaseous states as a result of the hot water releasing steam back to the liquid state. Because there is little room for these molecules to move, the water molecules, in the liquid state, stick to the sides of the beaker. Therefore, the efficiency of each insulator was shown through the end temperature and the degree of condensation.
All in all, this experiment was a simple demonstration of conduction and an easy way to test the efficiency of a variety of insulators. Conduction occurs when heat energy is transferred from a warm area to a cooler area, from molecule to molecule. In this experiment, heat energy was simply transferred from the water in the beaker to the outside environment. The water was warmer than the outside environment temperature, and therefore “escaped” from the water into the air.
It makes sense to me, and I could be wrong, to say that the reason that the foil was the best insulator is due to the fact that it is the most solid insulator. In other words, the foil’s structural molecules are the closest together, thus trapping the heat energy, and any gaseous water in the beaker at the greatest rate.
Although I did not test this, I would hypothesize that these insulators would work the same, or relatively similarly on alternative substances. In other words, foil would keep heat energy in these materials most efficiently, just like it did for water. The overall ability of these materials to retain heat, however, is a much more difficult question, as it brings in the concepts of heat capacity and the first law of thermodynamics. A substance with a higher specific takes longer to heat up because more energy is required in order to raise its temperature 1°. Due to this fact, a substance with a higher specific heat heats up slowly, holds a greater amount of energy, and cools down slowly. Therefore, if we were to test the efficiency of insulators on alternative substances, such as spaghetti or a hot dog, those substances with higher a specific heat will naturally take longer to cool down.
Jordan,
ReplyDeleteI really enjoyed reading about your experiment on heat. I also found that the aluminum foil trapped the most heat. I did not think about the condensation that formed and how that could have effected my experiment. You are absolutely right in the fact that more condensation was produced using the aluminum foil as a covering. That was not something that I paid attention to, however I should have. This is another reason why collaboration is so important in science. Sometimes, in order for an conclusion to be made, it takes the brainpower of more than one individual as well as the observations of different people.
Your reasoning as to why the aluminum foil worked the best also makes perfect sense. I tested out plastic as one of my insulators, which seemed as solid as the foil. This made me have to think a little harder as to the reason for the foil to work better. I concluded that the intended purpose of the foil was to keep hot foods warm or cold foods cool. With this in mind, there has to be a reasoning for the foil to have a sheen. I really think that the shiny material reflected the heat back down and into the water as to keep it trapped.
Which side did you face towards the water when you did your experiment. I put the shiny side down and the duller side pointing towards the outside. I think that this caused the light to not be reflected off of the foil as much as if I had the shiny side out. I wonder if that would have an effect on the experiment. It would be interesting to perform this experiment again using only foil and have one with the shiny side facing the hot water and one with the dull side facing it.
You also mentioned that the insulators should work the same with the different substances. I agree with this hypothesis. It was also interesting that you mentioned how some materials take longer to heat up or cool down. That is another consideration when looking at how well an insulator works. It is crucial that the substance be the same in all the insulators that are being tested. Having different materials with different energy needs to change the temperature could really skew the results.
You brought up some awesome points, as always. I am constantly intrigued by your thought process. Keep it up!