CHEN 3101 Lecture Notes - Lecture 16: Ne Win, Ideal Gas

• School: UMN
• Department: Chemical Engineering
• Course: CHEN 3101
• Professor: David Morse

Document Summary

Goal: how evaluate change in molar enthalpy, internal energy, entropy, etc. P = p(t,v) or v = v(t,p: ideal gas capacity. Cp(t) = lim(p --> 0) cp(t,p) = cv*(t) + r. Approx eqns of state: virial expansion (taylor expansion for nearly ideal gas, cubic eqns of state (van der waals and relatives) Virial expansions: systematic way of describing deviations from ideal gas. Let z = v(t,p)/vig(t,p) = pv/rt aka compressibility factor z --> 1 as p --> 0 or v --> infinity. Pv/rt = 1 + b(t)/v + c(t)/v2 + or pv/rt = 1 + btilda(t)p + ctilda(t)p2 + coefficients = functions of t this is good for p << pc (critical pressuresince can distinguish liquids and gases) Comments: 1: qualitative behavior looking @ limit as a = 0. Chen thermo page 1 if include a term isotherm. T < tc: generalized eqn of state (eos) --> not for specific fluidgeneric for all.