Question

Part 2: Demonstration of Thermal Energy Transfer Between Liquids

1. Fill one beaker with 100 mL of room-temperature water.
2. Fill a second beaker with 100 ml. of warm tap water.
3. Place a thermometer in each beaker. Record the temperature when it stops changing.
Question 5
How do you know that over time the thermometer will come to be the same temperature as the water it is in?
4. Carefully pour the room-temperature water mixture into the warm water. Place a thermometer in this
water. Record the temperature after it stops changing,
5. Record the temperature of the mixture again after 5 minutes and after 10 minutes.
6. Refill the first beaker with 100 ml. of room-temperature water.
7. Fill a third beaker with 100 mL of ice.
Question 6
What is the temperature of the ice? How do you know?

Answer 1

Answer to Question 5:
Over time, the thermometer will come to be the same temperature as the water it is in because thermal energy will transfer from the water to the thermometer (or from the thermometer to the water) until they reach a state of thermal equilibrium, where their temperatures are equal.

Answer to Question 6:
The temperature of the ice is 0°C (32°F). This is the temperature at which water freezes and turns into ice. We know this because the freezing point of water is a physical constant, which means that it is always the same under the same conditions (e.g. at sea level and standard atmospheric pressure).