Calorimeter Smarterscience Activity

In this activity I was tasked with creating a calorimeter to test and test ways to improve it. To start, I made it around a pop can. I would put the water in the can, and the flame would heat the bottom. To reduce heat loss i took a thin layer of home insulation, put some aluminum foil on one side and folded the edges over length wise along the insulation covering two thirds of that side. Next i wrapped the insulation around the can so the side with two thirds covered by foil was facing the can and used masking tape to tape the insulation closed. Then i used popsicle sticks to raise the can 10cm up off the surface of the lab bench by taping them onto the sides of the can, which i then wrapped in aluminum foil leaving a 2cm gap between the bench and the bottom of the foil. this was to contain radiation. Finally I covered the top of the can in a very thin layer of insulation which i would tape down and poke the thermometer through when doing the testing.

After I finished testing the calorimeter, i then decided to see how much of an effect adding 2cm of insulation along the can and down the foil over the popsicle sticks would have on the efficiency of it. My reasoning for testing this is due to what i was able to sense during the testing. when i placed my hands on the insulated parts i could feel a fair amount of heat through it, and when i placed my hands on the foil around the popsicle sticks I found it to be extremely hot. To me this meant that the calorimeter was losing a noticeable amount of heat throughout the test.

Findings

Test 1 -Unmodified-                                                                                                            

Run for 15 minutes, temperature collected and graphed every 0.5 seconds. Starting temperature of 23.6°C and ending temperature of 56.6°C. Calorimeter was filled with 100mL of water. At the highest point the bottom of the can was 10.2cm above the base of the lab bench. Candle had a starting weight of 9.92g and ending weight of 9.21g.

In this test the calorimeter absorbed and retained 13790.7J of heat, which is 19423.52113J of heat per gram of wax burnt.

Test 2 -Extra insulation around sides-

Run for 15 minutes, temperature collected and graphed every 0.5 seconds. Starting temperature of 22.4°C and ending temperature of 65.6°C. Calorimeter was filled with 100mL of water. At the highest point the bottom of the can was 10.2cm above the base of the lab bench. Candle had a starting weight of 9.20g and ending weight of 8.36g.

In this test the calorimeter absorbed and retained 18053.28J of heat, which is 21492J of heat per gram of wax burnt.

Significance of Findings

I found that by adding an extra 2cm of insulation around the sides of the can increased the efficiency of the calorimeter by about 10.65%. For me these findings show me that my calorimeter had a large loss of heat through conduction causing me to lose at least 10% of the heat energy, although it is likely that it`s losing a lot more due to other inefficiencies in the design.

Thoughts on Future Experimentation

If I were to continue experimentation with this calorimeter I would first work with reducing heat loss through conduction by adding more insulation around the sides and on top of the can and try to find at what point the insulation added would stop reducing heat loss by any significant amount. Next I would try changing the order of the materials i put on the calorimeter. For example, move the aluminum foil around the can to the very outside on top of the insulation, or add multiple layers of it with insulation between the layers of foil. After that i would try to prevent any air from getting in or out of the inside of the can to reduce heat loss from convection. I would likely start by sealing the top with aluminum foil and putting insulation over top. Finally, I would experiment with the height of the can above the lab bench and altering the size of the opening between the bench and the bottom of the aluminum foil.

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