| DCS # | DEMONSTRATION | REFERENCE | ABSTRACT |
|---|
| 4C20.00 | Phase Changes: Liquid-Solid | | |
| 4C20.10 | supercooled water | PIRA 1000 | |
| 4C20.10 | supercooled water | 4C20.10 | A small test tube of water is cooled in a peltier device and the temperature is followed with a thermocouple. |
| 4C20.11 | supercooling water | H-71 | Water in a small test tube is cooled to -4 C by placing in a dry ice/alcohol bath. Shake to freeze and the temperature will rise to 0 C. |
| 4C20.12 | drop freezer | AJP 39(10),1125 | 1971 Apparatus Competition Winner. Drops are placed on a copper plate with a tail in dry ice. A thermometer is placed in the copper plate and a mirror at 45 degrees allows easy observation of the drops. |
| 4C20.15 | supercooling in four substances | 26-5.15 | Four methods are given for supercooling various substances. |
| 4C20.20 | ice bomb in liquid nitrogen | PIRA 500 | |
| 4C20.20 | ice bomb | Hk-5 | An ice bomb is filled with water and placed in a salt water bath. |
| 4C20.20 | ice bomb | H-56 | The ice bomb takes half an hour to break when placed in a freezing mixture of ice and salt. |
| 4C20.20 | ice bomb | H-2a.1 | Just a picture. |
| 4C20.20 | ice bomb | Disc 15-15 | An ice bomb is placed in a liquid nitrogen bath. |
| 4C20.21 | ice bomb in liquid nitrogen | 4C20.21 | An ice bomb is placed in a beaker of liquid nitrogen in a plexiglass cage. |
| 4C20.21 | ice bomb - galv. pipe | AJP 44(9),893 | Use a galvanized coupling and plugs for a bomb and liquid nitrogen for a fast freeze. |
| 4C20.22 | expansion of freezing bismuth | H-55 | A hummock rises on the surface of bismuth as it freezes in a tube. |
| 4C20.23 | contraction of paraffin | M-20a.5 | Let a beaker of liquid paraffin freeze. |
| 4C20.30 | regelation | PIRA 500 | |
| 4C20.30 | regelation | 4C20.30 | Cut through a block of ice with a wire loop that has a heavy mass hanging from it. |
| 4C20.30 | regelation | Hk-4 | A copper wire under tension cuts through a block of ice. |
| 4C20.30 | regelation | Disc 15-16 | A mass hanging from a loop of thin stainless steel wire cuts through a block of ice. |
| 4C20.31 | regelation explained completely | TPT 3(7),301 | The complexity of regelation is examined by Mark Zemansky. |
| 4C20.31 | regelation | TPT 3(4),186 | Explanation of regelation. Copper cuts through faster than iron or thread. |
| 4C20.32 | regelation | H-57 | Substances that expand on freezing show a lowering melting point under pressure. Two blocks of ice, held together by hand, will freeze. Also complete directions for the standard demo. |
| 4C20.32 | crushed ice squeeze | H-58 | Crushed ice squeezed in a thick walled cylinder forms a solid block. |
| 4C20.33 | pressure and freezing point | TPT 28(5),260 | A letter disputing TPT 25,523 pointing out the difficulty in obtaining a uniform 0 C temperature in an ice bath. |
| 4C20.35 | liquefying CO2 | PIRA 500 | |
| 4C20.35 | liquifying CO2 | 4C20.35 | Press down on a piston on dry ice in a clear tube until at 5 atmospheres liquification occurs. |
| 4C20.35 | liquifying CO2 | H-59 | A strong bulb with a 1 cm square neck area is filled with dry ice and a 5 kg mass is added. The melting point of CO2 is about 5 atmospheres. Lift the weight slightly to freeze. |
| 4C20.36 | CO2 syringe | AJP 47(3),287 | Put some CO2 in a small transparent syringe and squeeze to liquefy. Can be shown on the OH. |
| 4C20.40 | freezing liquid nitrogen | PIRA 500 | |
| 4C20.40 | freezing liquid nitrogen | 4C20.40 | Put some liquid nitrogen in a clear dewar and pump until it freezes. |
| 4C20.40 | freezing liquid nitrogen | AJP 35(6),540 | In addition to the standard freezing by evaporation in a clear dewar - pop off the cork when the nitrogen is solid and it will instantly turn to liquid while the temperature remains below its boiling point. |
| 4C20.40 | freezing liquid nitrogen | H-109 | Pumping on liquid air will produce solid nitrogen at -210 C. Air passed slowly over the outside of the flask will condense out liquid air at atmosphere pressure. |
| 4C20.42 | freezing nitrogen modification | AJP 36(9),919 | The dewar has a smaller cross section in the lower part to prevent the frozen plug from rising to the pumping port. |
| 4C20.45 | fire extinguisher | PIRA 500 | |
| 4C20.45 | fire extinguisher | 4C20.45 | Shoot off a CO2 fire extinguisher. |
| 4C20.45 | CO2 expansion cooling | Disc 15-03 | Shoot off a fire extinguisher at a test tube of water, freezing the water. |
| 4C20.46 | CO2 cylinder | H-65 | Liquid CO2 from cylinder is released into a heavy bag, freezing the central stream by evaporative cooling. |
| 4C20.50 | heat of fusion of water | 4C20.50 | Melt ice in a beaker of water and measure the temperature. |
| 4C20.51 | heat of fusion of ice | H-54 | Melt some ice in a calorimeter with a known amount of water. |
| 4C20.52 | freezing lead | 26-5.2 | Insert thermocouple into molten lead and plot the temperature on an x-y recorder as it freezes. |
| 4C20.53 | freezing tin | H-46 | Tin is heated to 360 C and temperature readings taken every 30 seconds until the temperature reaches 160 C. Half the time the temperature remains at 230 C. |
| 4C20.54 | heat of fusion of water | 26-5.1 | Place a thermocouple cooled in liquid nitrogen in warm water. Plot temperature as ice forms and then melts. |
| 4C20.55 | heat of solution | PIRA 1000 | |
| 4C20.55 | heat of solution | 26-5.6 | A manometer shows cooling when hypo or ammonium chloride are added to water, heating when sulfuric acid is used. ALSO - equal weights of water and ammonium nitrate will lead to freezing. |
| 4C20.56 | heat of solution | H-50 | Heat is generated if sulfuric acid is dissolved in water. Cooling results if hypo or ammonium nitrate is dissolved. |
| 4C20.59 | latent heat heating | 26-5.3 | Two experiments that use the latent heat from one substance freezing to heat another. |
| 4C20.60 | heat of crystallization | PIRA 1000 | |
| 4C20.60 | heat of crystallization | H-48 | Prepare a supersaturated solution of sodium acetate or sodium sulfate and drop in a crystal to trigger crystallization. A thermocouple will show the change in temperature. |
| 4C20.61 | heat of crystallization | H-49 | A manometer hooked into the jacket of a double walled flask is used to detect the change in temperature of a sodium thiosulfate solution as it crystallizes. |
| 4C20.62 | heat of crystallization | 26-5.4 | A manometer indicates heating when a flask of supercooled hypo solution crystallizes. |
| 4C20.70 | project crystallization | H-44 | Project while crystallization occurs in a thin film of melted sulfur or saturated solution of ammonium chloride. |
| 4C20.71 | crystallization | H-45 | Crystallization from a conc. solution of sodium acetate or sodium hyposulfate. See also E-195 (lead tree) and L-122 (polarization). |
| 4C20.72 | water crystals in soap film | 26-5.12 | A ring with a soap film is cooled in a chamber surrounded by dry ice on the overhead projector. Water crystals form. |
| 4C20.73 | crystal growth on the overhead | 26-5.13 | Various organic compounds are used to show crystal growth between crossed Polaroids on the overhead projector. |
| 4C20.73 | crystal growth on the overhead | 26-5.14 | Tartaric acid and benzoic acid are melted together and the crystal growth on cooling is observed between crossed Polaroids on the overhead projector. |
| 4C20.74 | observing crystallization | 26-5.17 | Directions for building a microprojector useful for showing crystallization phenomena. |
| 4C20.90 | hard sphere model | AJP 45(4),395 | A two dimensional hard sphere model of a fluid shows propagating holes or flow if 4% of the spheres are removed. |
| 4C20.98 | Metglas 2826 | AJP 46(1),80 | Metglas 2826 is a metal that has been quenched from liquid to solid without crystallization. The mechanical, electrical, and magnetic properties are demonstrated. |
| 4C20.99 | Wood's metal | H-47 | The recipe for Wood's metal (melting point 65.5 C). |