What is Conduction?

•Conduction is the transfer of heat energy from one substance to another substance through direct contact.

Insulated Plastic Calorimeter and Lid: The calorimeters and lids will keep the heat of the hot water in the hot water calorimeter and the heat of the classroom out of

the cold water calorimeter.

The calorimeter lids have a slot for the heat transfer bar and a hole for the thermometer.

Aluminum Heat Transfer Bar:The Aluminum Heat Transfer Bar allows the two

substances, in this case water, to be in contact with one another. Once in contact, the aluminum heat

transfer bar allows heat to be transferred from one calorimeter to the other.

Stopwatch: The stopwatch is used to observe and record the temperatures of both

calorimeters every 4 minutes for a 20 time span of 5 hours and 20 minutes.

The Investigation• Boiling water from a hot pot was poured into one of

the calorimeters and labeled “Hot Water Calorimeter.”• Room Temperature water from the orange-cap bottle

was poured into the remaining calorimeter and labeled “Room Temperature Water Calorimeter.”

• The lids were used to cover the calorimeters.• The Aluminum Transfer Bar and the Thermometers

were inserted into both calorimeters.• The temperatures of both calorimeters were observed

and recorded for a 5 hour and 20 minute time period.

0:00 Minutes

Hot Water Calorimeter

Room Temperature Water Calorimeter

4:00 Minutes

8:00 Minutes

12:00 Minutes

• Is heat being transferred from the water in one calorimeter to the water in the other calorimeter?• How can you to tell?• In which direction did the heat

flow?

Questions:

There are two ways to tell that heat is being transferred:1. By the way the temperatures change on the thermometers.2. By touching the heat transfer bar. You can feel the heat move from the hot calorimeter, through the transfer bar, toward the room temperature calorimeter.

16:00 Minutes

20:00 Minutes

140:00 Minutes

Analyze the Graph:1. Over the first 20 minutes, where is the slope of the hot water calorimeter line graph the steepest; between 0-6 minutes, 8-14 minutes, or 16-20 minutes? 2. What does it mean when the slope of the line graph is steep?

Hot Water Calorimeter Line Graph

• Where the slope of the graph is steepest, the heat is being transferred the fastest.

• The heat was transferred the fastest at the beginning of the investigation.

0-6 minutes:

Dropped 8.5 °C

8-14 minutes:

Dropped 6.7 °C

16-20 minutes:

Dropped 3.9 °C

What do you predict would happen if

temperature readings were taken for 5 more

hours?

Question:

5 Hours and 20:00 Minutes: The two thermometers in the calorimeters will eventually read the same at room temperature.

• Predict what would happen in terms of heat transfer if you filled the hot water calorimeter to the top, but only filled the room temperature calorimeter up

¼ of the way to the top?

Question:

Answer:• The temperature of the room

temperature calorimeter would increase more rapidly than if the two calorimeters contained equal volumes of water.• The smaller volume of room

temperature water needs less heat for the temperature to increase.

Question:• How does the temperature difference

between the two calorimeters affect the rate at which the heat flows from the hot water calorimeter to the cold water calorimeter?

• In other words, does the heat flow faster when the temperature of the hot calorimeter is really hot and cold calorimeter really cold or when the two calorimeters are closer to the same temperature?

Answer:

• The greater the temperature differences between the two calorimeters, the faster the heat is transferred from the hot water calorimeter to the cold water calorimeter.