How Does Compressibility Chart Predict Final Pressure in a Heated Rigid Vessel?

  • Thread starter Thread starter MEAHH
  • Start date Start date
  • Tags Tags
    Thermo
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
Sign up Log in
1 reply · 3K views
MEAHH
Messages
9
Reaction score
0
Thermo Help! Compressbility

Homework Statement


Ethane in a rigid vessel is to be heated from 50 psia and 100 F until its temperature is 600 F. What is the final pressure of the ethane as predicted by the compressibility chart?


Homework Equations


Pr=P/Pcr
Tr=T/Tcr
Pv=zRT


The Attempt at a Solution


this is a constant volume process.
I found the z for the first state to be 0.95
I don't understant hoe to find the final pressure, i tried to solve 2 Pv=RT equations to get

z1T1/P1=z2T2/P2 but i am unable to find the second z factor so i am unable to solve for p2 and i going about this right
 
Physics news on Phys.org
? No, you should not be solving this using the ideal gas law. Instead, you should look up the compressibility factor of ethane on a compressibility chart and use it to find the final pressure. The compressibility factor is determined by the temperature and pressure of the gas, so you will need to look up the compressibility factor for the final state of 600 F and 50 psia. The final pressure can then be determined using the equation P = ZPcr, where Pcr is the critical pressure of ethane (47.7 psi).