Thermodynamics: Vaporization

Determine the amount of thermal energy contained in a specific quantity of steam (one gram) at a specific temperature (100°C). This amount of thermal energy is called the Latent Heat of Vaporization of water.

Lab Summary:

The phase change from gas to liquid involves a transfer of thermal energy out of the substance, but doesn't involve a temperature change for the substance. The thermal energy depends on the mass and the latent heat of vaporization (the amount of energy per gram needed to change phase at a specific temperature). Your students will measure temperature and the mass of condensed water to determine the energy required to transition water from gas to liquid, and compare this to the energy required to simply change the temperature of water.

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(student version)

Method:

Use a Fast-Response Temperature Probe to measure the change in temperature of a known mass of water as steam changes from gas to liquid in the water. Determine the latent heat of vaporization of the steam.

Here's What You Need:

Probeware

• PASPORT Fast Response Temperature Probe (3 pack) (PS-2135)
• Xplorer GLX Graphing Datalogger (PS-2002)
  (or alternate PASPORT interface -- see other options)

Other Materials

• Basic Calorimetry Set (TD-8557)
• Large Base and Support Rod (ME-9355)
• Clamp, Three-Finger (SE-9445)
• OHAUS Triple Beam Balance w/o Tare (SE-8723)
• Glass tube, 1/4" outside dia., 2" long
• Water, about 10 deg C cooler than room temperature, 1 L

Lab Manual:

This activity is included in Physics with the Xplorer GLX (PS-2826), complete with Teacher Information pages, student instructions and handouts, and sample data for a total of 35 probeware-based labs. For your convenience, we offer bundles which provide the probeware necessary for the activities in the manual. For more information on these resources and bundles, click here.