Formula to calculate critical temperature prssure and volume
Answers
Answer:
The real gas equation is given as
( P+n^2a/V^2)(V-nb)=nRT
where n= no. of moles
a & b are Van-der Waal constant. “a” signifies the attraction between the molecules and “b” is volume of a single molecule of the gas.
The critical point is the point on P-V plane isotherm where 1st and 2nd derivatives of P w.r.t V is zero(Critical point is a saddle point on P-V isotherm). After solving the got equations and given real gas equation we get
V*=3nb, T*=(8a/27Rb) and P*=a/27b^2
where P*, V*,T* are critical pressure, critical volume and critical temperature.
we see that P*V*/RT* = 3n/8
if we define Pr=P/P*, Vr=V/V*, and Tr= T/T* (These are reduced quantities ) then we get Reduced equation of state:
(Pr+3/Vr^2)(Vr-1/3)=(8/3n)Tr
So all the isotherms of P-V plane will lie on a single curve(reduced equation of state).
The critical point is that point at which the properties of the two phases(here liquid and ga) become identical
Answer:
In thermodynamics, a critical point (or critical state) is the end point of a phase ... At higher temperatures, the gas cannot be liquefied by pressure alone. At the critical point,