Heat Transfer Lab

Goal: To determine the relationship between heat energy and heat transfer

Background: Heat as a form of energy is not measured directly. The energy associated with heat is the vibration of molecules within the material. The faster the molecules move, the more heat that material has. The speed of the molecules is what is known as temperature. By measuring temperature, you can investigate the flow and transfer of heat energy from one object to another.

Materials: Two calorimeter containers, foam lids, aluminum transfer bar, thermometers, beakers, IR thermometer

Day 1 Procedure: Equal amounts of the same material at different temperatures

  • Put 200ml of water into the beaker and boil it on the hot plate
  • While you’re waiting for the water to boil, push the end of each leg of the aluminum bar through the slot in the center of each insulating lid. Carefully Insert a -200C to 1100C thermometer into the remaining slot of each lid
  • Test the fit of the lids on the calorimeter cups
  • Fill one cup with 200ml of room temperature water
  • Fill the remaining cup with 200ml of boiling water
  • Quickly secure the lids on the cups and take a starting temperature reading and record it on the data table
  • Record the temperature of both cups and the aluminum bar (use the IR thermometer for the bar) every 2 minutes for 30 minutes
  • During the down time of waiting, look at the three video clips:

Answer the quiz questions:

  1. Heat is the measure of ______
  1. What is the only method of heat transfer that doesn’t require matter? ______
  1. What method of heat transfer uses direct contact? ______
  1. What method of heat transfer uses fluids? ______
  • Plot your data on graph paper with the temperature of both calorimeters on the “Y” axis and the time on the “X” axis (turn this in at the end of class tomorrow)
  • Use your data and the graph to answer the following questions and share the answers as a group on Google docs:
  1. How do you know heat was transferred from one calorimeter to the other?
  1. In which direction did the heat flow?
  1. The lines on your graph do not cross although they appear to be getting closer as time increases. If you measured the temperature of each cup for a long enough time, would the two lines eventually cross?
  1. Where is the slope of the graph greatest?
  1. What does this tell you about the rate of heat flow as compared to temperature difference?
  1. The heat gained by one calorimeter should equal the heat lost by the other calorimeter. If both calorimeters contain the same amount of water, the temperature gain of one should equal the temperature loss of the other.

Did you observe this in your data? And why not?

Day 2 Procedure: Equal amounts of different materials at different temperatures

  • Heat 200 ml of water in a beaker on the hot plate
  • While waiting for it to boil, pour 200 ml of windshield washer fluid into one of the calorimeter cups and secure the lid
  • When the water boils pour it into the second calorimeter cup and secure the lid
  • Slide a thermometer into the slots on each cup and record the starting temperature of both liquids
  • Slide the aluminum bar into the slots on both cups
  • Record the temperature of both cups and the aluminum bar (use the IR thermometer) every two minutes for 30 minutes
  • Plot your results on graph paper as you did yesterday (turn both graphs in at the end of class today)
  • Use your data and the graph to answer the following questions and share the answers as a group on Google docs:
  1. How does this graph compare to the graph from Day 1?
  1. What does this graph say about the amount of heat needed to raise the temperature of windshield washer fluid?
  1. Windshield washer fluid is made from water and methanol. Methanol is methyl alcohol, a highly toxic, highly flammable liquid. (It can never be ingested!!)It is also an ingredient in anti-freeze for cars. Can you suggest a reason why the fluid does not freeze in its container under the hood of your car?
  1. Can you suggest a reason why the fluid freezes quickly once it is sprayed on your windshield on a very cold day?
  1. Some people suggest for the manufacturer to simply add more alcohol to the solution to prevent it from freezing. Is that a good idea? (think about the properties of methyl alcohol)

This lab counts as a group grade only. You should turn in:

  • Day 1 data table on Google docs (10 points) + graph (10 points)
  • Answers to video quiz on Google docs (10 points)
  • Answers to Day 1 questions on Google docs (5 points each = 30 points)
  • Day 2 data table on Google docs (5 points) + graph (5 points)
  • Answers to Day 2 questions on Google docs (6 points each = 30 points)