Design an experiment to show which materials are good insulatorsExperimentI am going to conduct an experiment to find out what materials are the best conductors by heating a certain amount of water to a certain and controlled temperature with a kettle and measure the temperature with a thermometer, I will use the same temperature and amount of water with each test, I will then put that heated water into a copper pot, this I will also keep the same, the copper pot will then have a cork with a small hole in, for the thermometer, placed into the copper pot, the temperature will then be taken every minute till a certain limit.
The results will then be compared with various covers as well as a copper pot without insulation, this will then help to tell me what materials make good insulators. To keep this experiment a fair test I will always keep the following the same after I have found ideal figures with my preliminary work:-The same amount of waterThe same temperature of waterThe same copper potThe same cork lidIn an ideal experiment, the same thermometer, room temperature and stop watch would also be used, but to keep these the same would be impractical.One of the best insulators known is air, knowing this will help me make a choice later when it comes to picking a material.EquipmentKettleCopper PotCorkThermometerMeasuring CylinderStop ClockVarious Materials (Bubble Wrap, Corrugated Card, Paper etc.)SafetyMake sure that the copper pot is in its final position before putting hot water in as moving it after may cause a burn.Do not overfill the copper pot, and keep into account that the cork lid will expel water.Place the copper pot on a sensible surface such as a heat proof mat.
Choices of Insulators:-Aluminum foilGreen bubble wrapSee-through bubble wrapPaperCardboardFiberPreliminary WorkI conducted preliminary work to find out the values of the variables I wish to use e.g. Water amount/start temperature etc.VariablesWhat Happens?Why?ThicknessReduce Heat LossMore Air TrappedWater AmountMore Water = More Heat EnergyGreater mass = more area to coolWater Starting TemperatureHigh Temp = More Heat LossBigger RangePreliminary Experiments50ml of Water at 65*C in a small copper container, no insulationTime (minutes)Temperature (*c)065163260358455553653752852950104811471246134514441543Time has now been limited to 10 minutes as onwards of that point shows little activity30ml of water at 65*C in a small copper container, no insulationTime (minutes)Temperature (*c)065162259356455553651750848946104580ml of water at 75*C in a small copper container, no insulationTime (minutes)Temperature (*c)0751722703684665656637628619601059Experiment50ml of water at 75*C in a small copper container, no insulationTime (minutes)Temperature (*c)0751722703674665656637608589571055From the preliminary results I have chosen to use 50ml of water at 75*c due to a reasonable range with green bubble wrap as insulation50ml of water at 75*c, green bubble wrap as insulationTime (minutes)Temperature (*c)075173271369467566665764862961106050ml of water at 75*c, Black shiny sided bubble wrapTime (minutes)Temperature (*c)075173272370469566665763862961106050ml of water at 75*c Green carpetTime (minutes)Temperature (*c)0751722703684665646637618609591057EvaluationI found some quite unexpected results from the experiment; the un-insulated pot actually maintained heat longer than the insulated pots, this could have occurred for several different reasons:-1. The water start temperature may have been recorded improperly.
2. The thermometer used may have been different than the one used with the insulated pots, this may have caused the problem.3. The copper pot may have been different4. The lid may not have been fit properly/ amount of time the thermometer was absent from the hole5. The water inside of the pot in the original experiment might not have been stirred, as the temperature will have differed in different places6. The room temperature may have been different than, this is likely to have caused the difference.
7. The copper pot may have been colder/warmer than usual to start8. Or a mixture of all of these.The eye level may not have been level with the meniscus of the thermometer and/or the measuring cylinder, this is vitally important as the temperature may have been read up to 2-3 *c wrong, and the measuring cylinder perhaps 3-4ml out, this may not sound like a dramatic difference, but together, they may have caused the results.This is why it would have been important to conduct all of the experiments on the same day with the exact same equipment while giving time for the pots to cool.