PURPOSE: To show Critical Opalescence.
DESCRIPTION: A sealed container with viewing windows and a manifold contains liquid sodium hexafluoride under 37 atm pressure. A steam generator is connected to the manifold to warm it.
Apply steam steam until the temp reads 42 C. Turn off the steam using a line switch. The cube will continue to warm up to 43.9 C where critical opalescence occurs. Above 43.9 C it is a gas.
EQUIPMENT: .
SETUP NOTES:
Leybold part number 371401
Pressure chamber for demonstrating the critical temperature
The disappearance of the line of separation between liquid and gas is observed
when the critical temperature is reached.
Phenomena of critical opalescence.
Technical Data
Liquid Filling: SF6 , sulfur hexafluoride
Critical temperature of liquid filling: 45.5 °C = 318.7 K
Critical pressure of liquid filling: 37.6 bar = 37,600 hPa
Max. temperature rating of the gaskets: 100 °C
Dimensions of the chamber: 5 cm · 5 cm · 6 cm
Hose nipple diameter: 8 mm
Weight: 0.9 kg
