Featured LAB: Thermometers

Featured LAB

272

Thermometers

Purpose

To examine how the volume of a liquid and a gas change in response to temperature.

Part 1: Liquid Thermometer

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Ken Karp Photography

Procedure

Follow the handout instructions to build a thermometer like the one shown here. Then mark the liquid level in the straw for these conditions.

  • room temperature

  • vial warmed by your hand

  • ice water

  • ice water with 1 tablespoon of salt per 200 mL water

  • boiling water (do not allow the thermometer to touch the bottom of the beaker)

Observations and Analysis

  1. What did you observe? What is happening to the liquid in the vial to make it move up and down in the straw?

  2. Create a scale for the thermometer. Assign numbers for the places you marked on the straw for boiling water and ice water. What numbers did you choose and why?

  3. Based on your newly created temperature scale, estimate the temperature in the room. How did you arrive at your answer?

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Part 2: Gas Thermometer

Materials

  • 250 mL beakers (3)

  • ice

  • 10 mL graduated cylinder

  • food coloring

  • test-tube holder—wire

  • hot plate

Procedure

  1. Set up three beakers: one with ice water, one with room-temperature water, and one with hot water (cooled enough so that it is no longer steaming). Add 1–2 drops of food coloring to each beaker.

  2. Hold the 10 mL graduated cylinder with a test-tube holder. Invert the graduated cylinder and immerse it in each beaker for one minute.

Making Sense

Describe how a thermometer works.