Honors ChemistrySpecific Heat LaboratoryName ______

Purpose: To calculate the output of a heating coil, and to calculate the Specific Heat of a liquid and a solid.

Materials (Lab equipment): Tap water, 100 mL graduated cylinder, 400 mL beaker (for water bath), 250 mL beaker, heating coil, thermometer, antifreeze, copper pieces (4), string, scissors, forceps, hot plate, heat resistant gloves, Styrofoam cup, Labquest digital data unit, digital temperature probe

Procedure:

Part 1: Specific Heat of a solid

You will need to use the Labquest data collection unit and a digital temperature probe. The reason why is because the change in the temperature of the cool water is fairly small in this experiment. This unit helps us get much more accurate data. Please have one person from you lab team work on setting up this unit, while the other person gets the other lab equipment ready to go.

Labquest unit directions:

  1. Turn on the Labquest unit. Plug the temperature probe into channel 1. The temperature should be shown on the screen. If the temperature is not shown on the screen, ask for help from your instructor.
  2. Make sure to check the upper right hand corner – look for “mode.” It should read “time based.” Also check the duration. Change it to 300 s if it doesn’t already have that value.

Part 1 Data Table:

Weight of copper pieces:______g

Weight of Styrofoam cup (empty)______g

Weight of cup + water______g

Initial temperature of metal______oC

Initial temperature of water in the cup______oC

Final temperature of water in the cup______oC

Lab directions:

  1. Fill a beaker about halfway with water. Using a hot plate, begin to heat the water to boiling.
  2. Mass 4 pieces of copper on the balance. Record the mass in your data table.
  3. Tie the pieces of copper together with a string and using forceps, gently lower the metal into the water being heated. Leave the metal in the water for at least 5 minutes.
  4. Find the mass of the empty Styrofoam cup. Record the mass in your data table.
  5. Using a graduated cylinder, measure out about 200 mL of water and empty the water into the Styrofoam cup. Mass the cup again and record the value in your data table.
  6. Place the temperature probe that is connected to your labquest unit in your Styrofoam cup. Make sure that you locate the cup on your lab bench fairly close to your beaker of boiling water.
  7. When the metal has boiled for 5 minutes, take the temperature of the boiling water with a regular thermometer. (We will take this value to be the same as the initial temperature of the metal)
  8. When you are ready to move the metal from the hot water bath to the cold water in the styrofoam cup hit the “play” button in the lower left corner of the screen. The calculator will begin to measure the temperature of the water and graph the data. Make sure you record the lowest temperature that it displays.
  9. Use the forceps to grab the string that holds the pieces of metal together. Quickly move the metal from the beaker of boiling water to the Styrofoam cup. Do not allow the metal to touch the probe. Keep an eye on the temperature as it rises. Make sure to record the highest temperature reached.
  10. Hit the “stop” button in the lower left hand corner if the program is still running.
  11. Use the stylus with the Labquest unit to obtain the initial temperature (lowest temperature) and the final temperature (highest temperature). The temperature readings are visible on the right hand side of the screen.
  12. E-mail one or more members of your lab group the data and graph from lab. You may need to include these in your lab report. You do this by:

Text file directions (this the time/temperature data)

a)Select fileb) select Emailc) select text file d) follow the directions

Graph directions (this is the graph of your experiment)

a)Select fileb) select Emailc) select graph d) follow the directions

  1. Clean up. The only pieces of equipment that you need to keep for part 2 are the graduated cylinder, the beaker, and the thermometer (or the Labquest unit and digital temperature probe). Do not throw out your Styrofoam cup.

Part 2:Specific Heat of a liquid

Part A: Calculating the output of a coil

Note: Never have the coil plugged in when it is not in a liquid – it will burn out!!!!

Procedure: This procedure is written for using a traditional thermometer. If you wish to use the labquest unit, you may use it for this portion of the lab. Whatever method you use to measure temperature, you must use the same way for parts 2A and 2B.

  1. Weigh an empty 250 mL beaker and record the mass in your table.
  2. Use a graduated cylinder to measure approximately 200 mL of water and add the water to the beaker.
  3. Weigh the beaker and water and record the mass.
  4. Use a thermometer to record the initial temperature of the water. Leave the thermometer in the beaker. Don’t let it touch the coil.
  5. Place an unplugged heating coil into the water.
  6. Plug the heating coil in for exactly 5 minutes and record the temperature you reached at the end of that time.
  7. Unplug the coil, remove it from the beaker and cool it by running cold tap water over it for a minute or two.

Part 2A Data table:

Weight of beaker (empty)______g

Weight of beaker + water______g

Initial temperature of water in the beaker______0C

Final temperature of water in the beaker______0C

Part 2:Specific Heat of a liquid

Part B: Calculating the specific heat of antifreeze

Note: Never have the coil plugged in when it is not in a liquid – it will burn out!!!!

Procedure: This procedure is written for using a traditional thermometer. If you wish to use the labquest unit, you may use it for this portion of the lab. Whatever method you use to measure temperature, you must use the same way for parts 2A and 2B.

  1. Weigh an empty 250 mL beaker and record the mass in your table.
  2. Use a graduated cylinder to measure approximately 180 mL of antifreeze and add it to the beaker.
  3. Weigh the beaker and antifreeze and record the mass.
  4. Use a thermometer to record the initial temperature of the antifreeze. Leave the thermometer in the beaker.
  5. Place an unplugged heating coil into the antifreeze.
  6. Plug the heating coil in for exactly 5 minutes and record the temperature you reached at the end of that time.
  7. Unplug the coil, remove it from the beaker and cool/clean it by running cold tap water over it for a minute or two. Return your antifreeze to the bottle.

Part 2B Data table:

Weight of beaker (empty)______g

Weight of beaker + antifreeze______g

Initial temperature of antifreeze in the beaker______0C

Final temperature of antifreeze in the beaker______0C

Lab Report Requirements: On a separate sheet of paper ( The rest of this report must fit on one piece of paper – staple that paper to the back of this handout):

  1. Calculate the output of the coil in calories
  2. Calculate the Specific Heat of the antifreeze
  3. Calculate % error for Cp of antifreeze – accepted value = 0.62 cal/gCo
  4. Calculate the Specific Heat of the copper pieces
  5. Calculate % error for Cp of copper – accepted value = 0.385 J/gCo

6. Write T + D’s for the lab – one for part 1 and one for part 2

Make sure that you show all work, list units, and use proper significant figures.