2A20.10-Capillary Tubes

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Video: Watch this demo

Description: This is a set of capillary tubes of various diameters used to show capillary rise with water. This is a good demo to follow Pascal’s vases (2B20.40).

Equipment:

  • Capillary tube apparatus
  • Food coloring
  • Pyrex Beaker
  • Water

Setup Procedure:

  1. In a beaker, mix water with food coloring.

Demonstration Procedure:

  1. Pour the colored water into the main water reservoir.
  2. Note that the water is able to go higher in the smaller diameter tubes.
  3. This is an illustration of the Capillary action. Surface tension pulls the liquid column up until there is a sufficient weight of liquid for gravitational forces to overcome the intermolecular forces. (Description courtesy wikipedia:capillary action)