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How did liquefied nitrous oxide freeze water in a red-hot crucible?. Explain that rapid evaporation removed heat while a vapour cushion prevented direct contact between the water and the hot platinum. Frame the account as a reported nineteenth-century experiment and include the pressure and temperature figures supplied by the source.

How liquefied nitrous oxide froze water in a red-hot crucible

The nineteenth-century source reports that liquefied nitrous oxide, or laughing gas, could freeze water placed in a red-hot platinum crucible. The effect depended on two separate processes: rapid evaporation removed heat from the surroundings, while a vapour cushion prevented the water and the liquefied gas from making direct contact with the hot platinum.[1]

The reported experiment and temperatures

According to The World of Wonders, the nitrous oxide was liquefied under a pressure of 450 pounds per square inch. When released, its rapid evaporation produced a temperature nearly 200 degrees below water’s freezing point. Under an exhausted air-pump receiver, the source says the cold reached very nearly 300 degrees below the temperature of ice.[2]

The reported demonstration placed some of the liquefied gas in a red-hot platinum crucible, then added a small quantity of water. Despite the crucible’s intense heat, the water was said to turn into ice.[3]

Why the water could freeze beside hot platinum

  • Rapid evaporation removed heat. Once the compressed nitrous oxide was released, it rapidly returned toward its gaseous state. That change required a large input of heat, which was drawn from the surrounding objects, causing intense cooling.[4]
  • A vapour cushion blocked direct contact. The source compares the effect with a drop of water dancing on nearly red-hot metal: evaporation forms a thin layer of vapour between the liquid and the hot surface.[5]
  • The cushion reduced heat transfer from the platinum. This vapour layer acted as an insulating cushion, preventing direct contact between the water and the red-hot platinum while the evaporating nitrous oxide cooled the nearby material.[6]

In short

The account is not that the hot platinum itself became cold. Rather, the liquefied nitrous oxide evaporated so rapidly that it carried heat away, and the intervening vapour layer prevented the water from being directly heated by the platinum. The source therefore presents the freezing as a brief balance between powerful evaporative cooling and suppressed contact heat transfer.[7][8]