Calorimeters

[Leewon Koo 2K]

Hello,
I was just curious as to if we used a more homemade calorimeter (like the one with the styrofoam coffee cup mentioned in lecture) would we have to take into account any additional error? Would it be less accurate or is the difference negligible?
Thanks!

[Ankit Budhiraja 3D]

Based on my understanding of the usage of scientific instruments in subjects like chemistry it is an important consideration to understand the influence of error when experimenting. As we know it is very difficult to get 100% accurate and precise data all the time, especially in circumstances where our instruments may not be completely accurate. Alongside this, human error is common and a very possible contributor to slightly influenced data and observations. Keeping this in mind, it is likely that the error produced by a homemade calorimeter would be greater than that of a proper calorimeter in a lab. Despite this, I think it depends how minuscule the values which are being dealt with are to determine if the error is negligible or not.

[Julian Wang]

Hi Leewon. You are correct in supposing that using a homemade calorimeter would introduce additional error. As mentioned in lecture, the most ideal form of a system and its surroundings (an isolated system, where there is NO transfer of energy or matter) does not exist in the real world. In professional laboratories, calorimeters are specially designed with maximal insulation so that the energy lost by the system to the surroundings is minimized. However, this value is still never zero, and this loss is only exacerbated by less effective insulation. In the case of a layer or two of styrofoam cup, the calorimeter would certainly function decently but the amount of heat loss and resulting inaccuracy would be significant. The difference in this case is not negligible for the purpose of actually investigating the properties of a sample. Hope this helped!

[Elise Tsai 3I]

Hi, I had somewhat of a similar question regarding calorimeters. When we are creating these types of calorimeters with different materials such as styrofoam cups, are we supposed to take into consideration the specific heat capacity of the styrofoam cup along with the contents within the system? Or are we supposed to assume that it has no influence on the overall transfer of heat? Thanks!

[Ankit Budhiraja 3D]

Hi Elise, I think that either method could be used to use a homemade calorimeter. I think this goes hand-in-hand with the other question regarding accounting for additional error with the usage of homemade instruments in science. Specifically, I think that accounting for the heat capacity of the styrofoam cups would be useful in its ability to help you better gauge heat and volume. While this is the case, not accounting for this specific heat capacity of the material would negatively influence the accuracy of your results, but could be attributed to error as a result f the usage of instruments or human error. I think either way is possible, but reporting the heat capacity of styrofoam would be useful to achieving more accurate results.