THERMODYNAMICS - CHANGE OF STATE

T.1(1) - Cryophorus

T.1(2) - Metal Can

T.1(3) - Liquid Nitrogen Demonstration

T.1(4) - PVT Models for CO2 and H2O

T.1(5) - Pulse Glass

T.1(6) - Supercooled Demo


T.1(1) - CRYOPHORUS

It demonstrates freezing by evaporation.

This glass tube has a bulb on each end partly filled with water at reduced pressure so that the vapor content of the tube is high. When one bulb is placed in a mixture of dry ice and alcohol, water in the upper bulb evaporates so quickly that it freezes. Light is projected through the tube to show the ice crystals forming.

The tubes overall length is 33 cm

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T.1(2) - METAL CAN

It is a light metal can, about 20 cm x 10 cm x 25 cm, with a threaded lid. A little water is poured in the can and it is heated over a flame. As the water boils and the can is filled with steam, set it aside and close the lid, sealing it tightly. After a while, as the steam begins to condense, the atmospheric pressure crushes the can.

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T.1(3) - LIQUID NITROGEN DEMONSTRATION

Many objects may be used to demonstrate the law of internal heat as they have their temperatures lowered to the liquid Nitrogen's temperature.


24 Hour notice required for setup since we get the liquid Nitrogen at SSC

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T.1(4) - PVT MODELS FOR CO2 AND H2O

These models show the thermodynamic surfaces for CO2 and H2O, representing the P-V-T relations for all phases: gas, vapor, liquid, and solid. The exaggerated scale of the transitions makes easier the visualization of the volume changes as will as all the behavior of CO2 and H2O throughout their change of state. Each model is molded in a 25 cm side cube, with highly visible colors.

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T.1(5) - PULSE GAS

For demonstrating the increase in vapor pressure with temperature. Two connecting glass bulbs are partly filled with a volatile, tinted red liquid and with the air partially evacuated. Heat from one's hand is sufficient to cause rapid transfer of liquid into the other bulb, where it bubbles rapidly.

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T.1(6) - SUPER COOLED DEMO

It demonstrates crystallization and the subsequent release of latent heat. The super-cooled and super-saturated pack (15 cm x 7.5 cm) contains a soltion made of sodium acetate and water, and a beryllium-copper disk (1.5 cm). Flexing the disk triggers two simultaneous and rapid chain reactions. Stored energy is released throughout the solution as it crystallizes. In about five seconds, the pack can reach a temperature up to 40°C (130°F) and will stay warm for about two hours. It is reusable and there are three samples in the lab.



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