Category Archives: Entropy And The Second Law

Steel Wool and Battery

Demo: TH-F-SW
Pira Index: 4F 00.00

Lab Equipment  Directions
  1. steel wool
  2. 9 Volt battery
Option: can be used to simulate a fuse.
  1. At one end of the steel wool pull some fine strands out from the ball of the steel wool.
  2. Carefully lay a strand across the battery terminals.
  3. Repeat with several strands to increase the burning time.

The steel fibers burn quite well. Use caution to not let the fire get out of control.

Stirling Cycle Engine

Demo: TH-F-SE
Pira Index: 4F 30.10

Lab Equipment  Directions
  1. stirling cycle engine
  2. ethanol dropper
  3. visible stirling engine
  4. small coffee pot
  5. matches
  1. Fill well with Ethanol and then put covering make sure it is wet with ethanol before lighting it with a match.
  2. Rotate the top of the flywheel towards the front of the motor. Let the engine cool between runs.
  3. Plug in the coffee pot and set the visible stirling engine on top of it. As the water gets warm with wooden propeller may need a nudge to get started.

Hero’s Engine with LN2

Demo: TH-F-HL
Pira Index: 4F 30.01

Demonstrates the law of action and reaction, and the conversion of liquid to gas to mechanical energy.

Video link: Hero’s Engine LN2

Lab Equipment  Directions
  1.  New Hero’s Engine
  2. Tail Nalgene Container
  3. water
  4. funnel
  5. styrofoam cup
  6. dewar with Liquid Nitrogen 1/2 full
Before using, lubricate the bolt with 3 in 1 oil or just light oil.
  1.  Setup as seen in photo.
  2. Take the styrofoam  cup and dip into the dewar of liquid nitrogen and fill cup.
  3. Using the funnel, pour the LN2 into the plastic drinking bottle.
  4. Tighten bottle to the cap and PVC pipe assembly.
  5. Hold the other end of the PVC firmly and lower the bottom of the bottle into the Nalgene container (1/3 full of water).
  6. As soon as the bottom of the bottle touches the water, it will begin to boil and pressurize. The nitrogen gas escaping will cause the bottle to turn at a high rate of speed.

Hero’s Engine

Demo: TH-F-HE
Pira Index: 4F 30.01

Lab Equipment  Directions
  1. Hero’s engine with attached wrench
  2. propane torch
  3. 20 – 50ml beaker
When storing on shelf, remove steam chamber and set on base. Before using, lubricate the screw top with silicon grease.
  1. Pour about 20ml of water in the steam chamber (should have been removed after last use).
  2. Screw chamber back onto brass nut.
  3. Heat the chamber with the torch. The chamber will begin rotating.

Entropy of Mixing

Demo: TH-F-EM
Pira Index: 4F 10.00

Lab Equipment  Directions
  1. Erlenmeyer flask – 500ml
  2. small funnel with flexible tube and glass capillary tube attachment
  3. beaker – 400ml
  4. food coloring
  5. salt
  6. stirring rod
  1. Put 300ml of distilled water with yellow food coloring in the flask.
  2. In the beaker combine 100ml of how water, a drop of blue food coloring and slowly stir in as much salt as will dissolve – around 10g. Allow to cool.
  3. Use funnel and attachment and slowly pour the cooled blue salt water into the bottom of the flask. Be careful not to shake or agitate the yellow layer.
  4. Carefully remove the funnel and observe the color separation.
  5. At the end of the demo shake the flask and show the irreversibility of the mixture.

Exploding Gas Can

Demo: TH-F-EG
Pira Index: 4F 10.45

Lab Equipment  Directions
  1. special 1 gallon paint can
  2. propane torch or match
  1. Fill can with natural gas.
  2. Set on table.
  3. Ignite the hole area of the lid.
  4. Be sure the lid won’t hit the lights above the table.
  5. Wait four or more minutes for the flame to get small enough to ignite the gas in the can.

Caution: When the flame almost shrinks away stand back and prepare for ‘the big bang.’