Monday, 30 June 2014 14:52

## I6-52: ENTROPY - FOUR BALLS IN GAS DIFFUSION MODEL

• ID Code: I6-52
• Purpose: Demonstrate that an ordered state is statistically possible.
• Description:
Place two balls of each of two different colors in the diffusion apparatus. To start, either place all four one the same side of the apparatus; or place two of one color on one side of the apparatus, and two balls of another color on the other side. Start the machine going with the hole between sides open.
##### Engagement Suggestions
• Encourage students to notice that although statistically it is less probable, the arrangement of both orange balls on one side and both green balls on the other side will happen occasionally.
• Ask: Is this as likely to happen using three balls of each color? With four?
##### Background
This is essentially showing the exception to the general principle of demonstration I6-21. With a small enough number of balls in the model, it is statistically possible to “reverse entropy” to a limited extent – that is, occasionally, the balls will randomly organize themselves so that they are once again sorted by color.
• Availability: Available
• Loc codes: FS1
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Illustrates the molecular nature of gas pressure Read More
• #### I6-02: NITROGEN DIAMETER AND MEAN FREE PATH

Experimentally determine the diameter of the nitrogen molecule and to determine the order of magnitude of the mean free path Read More
• #### I6-03 EQUIPARTITION OF ENERGY

Demonstrates equipartition of energy Read More
• #### I6-11: BROWNIAN MOTION WITH TV

Demonstrates equipartition of energy Read More
• #### I6-13: AIR TABLE - MODEL OF BROWNIAN MOTION

Simple model of Brownian motion. Read More
• #### I6-21 GAS DIFFUSION - MODEL

Models gas diffusion through a small hole Read More

• #### I6-24: DIFFUSION VELOCITY

Show that the diffusion velocity is proportional to the RMS molecular velocity. Read More
• #### I6-25: DIFFUSION - DISTRIBUTION OF PING PONG BALLS

Demonstrate on a macroscopic scale using ping pong balls how random molecular motion causes substances to diffuse. Read More

• #### I6-32: MOLECULAR MOTION DEMO - RANDOM MOTION IN GASES

Model random molecular motion. Read More

• #### I6-37: MOLECULAR MOTION DEMO - VAN DER WALLS FORCES

Introduce the concept of attractive force between molecules. Read More

• #### I6-40: MOLECULAR MOTION DEMO - SOLIDS

Model the behavior of solids. Read More
• #### I6-41: MOLECULAR MOTION DEMO - LIQUIDS

Model the behavior of liquids. Read More
• #### I6-51 ENTROPY - SORTING MARBLES

Demonstrates that increasing entropy requires less energy than decreasing entropy Read More
• #### I6-52: ENTROPY - FOUR BALLS IN GAS DIFFUSION MODEL

Demonstrate that an ordered state is statistically possible. Read More
• #### I6-61: MAXWELL'S DEMON

Example of a "Maxwell Demon." Read More
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