Say I have a 1 liter sealed pressure tank, and I fill it with 500mL of water. Then, I slowly heat the tank up to 2000 degrees Celsius. Does the water inside vaporize and become steam? Does the steam become supercritical or does it reach 2000 degrees celsius? What is the pressure inside the tank?
1 Answer
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Assuming that there is no air in the tank (only liquid water and water vapor), water in the tank will vaporize enough to pressurize the tank to the vapor pressure of water at its current temperature, according to the Antoine equation.
See https://en.wikipedia.org/wiki/Antoine_equation.
As the tank continues to heat up, the water will reach its critical temperature at 374 deg C, at which point it will go supercritical and consist of only one phase. At 2000 deg C, the pressure will be somewhat above the critical pressure of 218 atmospheres, and you should be able to calculate it with the adjusted ideal gas equation of $PV=znRT$, where values of "z", also known as the compressibility factor, can be found here:
answered Apr 21, 2020 at 17:24