Summary

In this lab, students will explore the process of condensation. Students will investigate how water vapor condenses, and then they will conduct a comparison test to see if cooling water vapor has an effect on the rate of condensation.

Grade Level

Elementary or middle school

Objectives

By the end of this lab, students should be able to

• Describe that the process of changing matter from a gas to a liquid is called condensation.
• Explain that the surrounding temperature can affect the rate of condensation for a gas.

Chemistry Topics

This lab supports students’ understanding of

• States of Matter
• Phase Changes
• Condensation
• Physical Changes

Time

Teacher Preparation: 20 mins

Lesson: 50 minutes

Materials

• 2 pitchers
• Hot water- from the tap or use a warming pot/hot plate to warm up water
• Ice cubes (one per group)
• 1-cup measuring cup
• 2 Tall clear plastic cups (per group)
• 2 Wide clear plastic cups (per group)
• Magnifier
• Paper towels
• Sauce pan/pot with lid
• Timer (one per group)

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.
• Exercise caution when using a heat source. Hot plates and/or heating devices should be turned off and unplugged as soon as they are no longer needed.
• Be cautious when moving around the heat source. Do not reach over it, tie back hair, and secure lose clothing.
• Warm students about handling the hot tap water, exercise caution and ensure heat protective gloves are available for use.

Teacher Notes

• This activity calls for both small and wide clear plastic cups. Be sure the cups fit together, as shown in the picture. The wide cup should be used to hold the hot warm, and is placed on the bottom. The small cup is turned upside down and placed in the wide mouth cup. They should make a seal together. Be sure that the smaller cup, that will be inverted is completely clear.

• You will need a way to warm water for the initial demonstration. I suggest using a sauce pan and single burner.  Place the water on the burner and wait about 10 minutes before starting the demonstration (this will be used for students to answer the prelab questions). Leave the lid off to get started. If a single burner/saucepan is not available, consider using a microwave to heat the water or recording the process at home and showing the students a video recording in order to complete the prelab demo.
• You will need hot water for the experiment, but please note that it does not and should not boiling or extremely hot for the experiment portion. Using hot tap water is recommended.
• Depending on what is available in your classroom, students can obtain hot water for the experiment from the tap, or they can use a hotplate or microwave to heat the water. Make sure you have proper heat protective gloves/oven mittens available for students to use.
• Before you have students start working on the activity, have a discussion about where they believe they have experienced condensation and what their definition is.  Use examples such as a glass of lemonade during the summer, fogged up windows in the winter, etc.
• I have students work in groups of 2-3 for the lab.
• During the experiment when students put the ice cube on top of the cup they should see that the rate of condensation increases due to the temperature decrease outside of the cup.