Question

In a laboratory a vessel was built which can sustain high pressure, thermostats and pressure gauge were connected, assuming closed system, dry ice was introduced in closed vessel, the temperature of vessel was increased the sublimation of dry ice resulted in formation of gaseous carbon dioxide increasing pressure in vessel, the increased pressure and temperature resulted in liquid carbon dioxide formation, after more heating critical temperature was reached and superfluid carbon dioxide was obtained, at these state gas and liquid phases became indistinguishable, ice was put upon vessel surface which resulted in decrease of temperature and the liquid carbon dioxide appeared again. If we see typical pressure vs volume diagram it is observed that above critical conditions it is not possible to condense fluid by reducing temperature since the point will lie above the dome, then how come we see condensation of superfluid carbon dioxide in our experiment ?

Note: the boundary liquid gas interface was seen disappearing in as it's typically seen in superfluids hence it's confirm that we had superfluid carbon dioxide.

Answer 1

The condensation of superfluid carbon dioxide can occur by reducing the temperature through the addition of ice, despite being above the critical temperature. The disappearance of the boundary between the liquid and gas phases confirms the presence of superfluid carbon dioxide.

Step-by-step explanation:

In this experiment, the formation and condensation of superfluid carbon dioxide are observed. Above the critical temperature, it is not possible to condense a fluid by reducing temperature.

However, in this case, the condensation of superfluid carbon dioxide is achieved by reducing the temperature through the addition of ice. The boundary between the liquid and gas phases disappears in superfluids, which confirms that superfluid carbon dioxide was obtained.