Question

2) a) Find an expression for Cp in terms of Cy. Does this make sense? Explain. b) Calculate Cp for a van der Waals gas in terms of V, T, and Cy.

Answer 1

N a c 1 is defined as the molar gaseous system of mass of a pressure is defined as the of the system per degree that is ! OLI 175) heat capauty of a one mole of constant increase in enthalpy rise in temperature. W is gaseous volume фиц%94 fare. that defined as the molar system of mass one es defined as the 0 Ке" 84ftем 205 heat capauty of a mole of constant increase in internal dеалее. Ұk a fелеа is ! a

40 4, (ис Кувд Илоi - ТИ әo + Pəy , we getir Putting this value of an is Cp = (put Porn 89 le DUL DT COT at / For I mole of an ideal gas we know ! PVRTO now, differenting with respect to temp. at const pressure Putting Plow from @ in ega 10: - the value of pe wt R in and R molar const. hear copaures at volume (W) is Thus, the difference const pressure ( ) the gas constant -

(2T ре Lowru, p(2) DH 2 dvd por do 4 = 24), FOV). — As we know? do = ou du tou di COV COT a dul dut wat avo The partial derivative of t with respect to or constant pressure is or sul = (aul or tw o От е дv /, а р Petting value of oul from egr 0 in U | JV & Cu + pl vt (OTP temp. 0 P 6) 4-6 s (av) (ar) + Plan For a vanderwaal's gas &-

V 2 The partial implicit derivatue of the differentiation & is or volume you get by your ey / 0 4 0 ) = 0 1 Vb After implicat differentiation & 2 + 1 - 2a + 2 y J) = 0 -) Cov) - / () 7(13) *= 20/03 J. s RT TXERTIRI - 2a. RT 1 x vb Tub Trb? v3. a R/ Li-[zax (vb) 2 / [RT v3T 7- [2aX(v1) 1 / [RT VE) 2