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Models of Thermo & Stat Mech

  • I3-31: IDEAL GAS LAW - VOLUME OF ONE MOLE

    I3-31
    Demonstrate that one mole of gas occupies 22.4 liters at STP.
    Pour liquid nitrogen into the small beaker and let it boil down to about 35 ml. The density of liquid nitrogen is 0.808 g/ml, so one mole has a mass of 28 grams and occupies about 35 ml. Install the neck of the balloon over the beaker, and allow the liquid nitrogen to evaporate, filling the balloon. Determine the average circumference of the balloon and from that calculate the diameter. The approximate volume of one mole of nitrogen gas at atmospheric pressure is then V= 4 pi r3/3, which can be readily calculated. This determination is good to better than ten percent.
    I3, I0

  • I3-41: BOYLE'S LAW - PROJECTION

    I3-41
    Demonstrate Boyle's law.
    Connect the piston tube to the pressure gauge. Read off several values of pressure and volume for different piston positions to show that PV=constant.
    I3

    i3-41ai3-41b

  • I3-51 CHARLES' LAW - PROJECTION

    I3-51
    Demonstrates Charles' law
    A hollow sphere filled with air is connected by a tube to a pressure gauge on an overhead projector. Place the sphere in ice water (T=273K) and in boiling water (T=373K), and read the pressure for each as well as at room temperature.
    I3, I0

  • I4-01: PVT PHASE DIAGRAMS FOR CO2 AND H2O

    I4-01
    Three-dimensional PVT phase diagram models.
    These are carefully labelled, three-dimensional, four-color pressure-volume-temperature phase diagrams for CO2 and H2O .
    I4

    i4-01a

  • I4-02: PVT SURFACE - TRANSPARENT

    I4-02
    Illustrate aspects of phase transitions.
    This is a "generic" phase diagram on which the instructor can write details using various colors of felt tip pens. Projections can easily be seen, and the overall geometry can be observed because the model is transparent.

  • I6-01 GAS PRESSURE - MODEL

    I6-01
    Illustrates the molecular nature of gas pressure
    A vibrator motor is activated causing chaotic motion of a group of ball bearings in a clear plastic container. The upward motion of the ball bearings pushes a black plastic plate upward, indicating the upward force of "air pressure" on the plate. Increasing the speed of the motor by turning up the variac increases the average speed of the balls and pushes the plate up further, modeling a greater pressure.
    I6, PW1

  • I6-61: MAXWELL'S DEMON

    I6-61
    Example of a "Maxwell Demon."
    A Maxwell demon is some gizmo which presumably allows you to do something which otherwise might be statistically unlikely. For example, the system photographed contains ten balls which are apparently identical except that five are white and five are black. If you rotate the device with the big end up you can separate the black and the white balls, and allow only one color of balls to fall into the neck, as shown in the photograph above. You act as the "Maxwell Demon."

    i6-61a