Molar volume of hydrogen at different P, T values
Thread Content
Hydrogen is special; the compressibility factor method cannot be used to determine its molar volume. Let’s discuss what methods can be employed to find it
It can be calculated using the formula: P1V1/T1=P2V2/T2.
Why can’t the compressibility factor be used to determine the molar volume of hydrogen? Can’t we use the ideal gas equation under conditions where the pressure isn’t too high and the temperature isn’t too low? I’d like to hear the insights of those with expertise in theory
For the gases hydrogen, helium, and neon, due to their extremely small molecular volume and high compressibility, the values of their compression factors differ from those of other gases. The formulas for calculating the specific pressure and specific temperature are respectively: Pr = P / (Pc + 8), Tr = T / (Tc + 8), where P and Pc represent the actual pressure and critical pressure, respectively, in MPa； T and Tc denote the actual temperature and critical temperature, respectively, in K ； The gas compressibility factor Z can be found from relevant manuals using Pr and Tr, and then it can be calculated using PV=ZnRT. However, at pressures below 1 MPa, treating it as an ideal gas makes little difference.
There are many empirical formulas for this; the original poster can refer to the book \"Chemical Engineering Data\".