Thermal Conductivity of Aluminum

 In this experiment, an aluminum can, hot water, cold water, and Styrofoam cup were used. Hot water was put inside the aluminum can which was then immersed into the cold water in the Styrofoam cup.

As soon as the aluminum can is immersed, the temperature outside and inside of the can are measured and recorded. Below is the graph of heat vs. time. Heat was calculated from the recorded temperature.

Then, the cross sectional area of the can was calculated.

The surface area was calculated and it is equal to the area of the circle of the bottom of the can and the area of the rectangle that makes up the cylinder. 

Then, the thermal conductivity of aluminum was calculated.

Both k values are not closed to the actual thermal conductivity of aluminum. It would seem that this is not the right way to calculate the thermal conductivity of aluminum. However, I do not know the correct way and this is my best guess. I understand this is inexcusable, but I do not have anything more.