This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Chemistry 444 B Hour Exam #2 March 26, 2008 Each problem is worth 20 pts. 1) Over the pressure region from 0 to 600 bar, the fugacity coefficient, γ , for CO 2 at 200 K is given by the following expression: 6 2 0.70 3.33 10 ( 300) for given in bar. P P γ − = + × − a) (5 pts) Sketch f/P vs P from 0 to 600 bar, where f is the fugacity. f/P= γ , so Gamma 0.600 0.700 0.800 0.900 1.000 100 200 300 400 500 600 P r e s s u r e i n b a r b) (5 pts) What is the fugacity of CO 2 at 450 bar? ( ) 6 2 6 2 / 0.70 3.33 10 ( 300) so, 0.70 3.33 10 ( 300) f P P f P P P γ γ − − = = + × − = × = × + × − at P = 450 bar, f = 450 x (0.775) = 349 bar c) (5 pts) Calculate μ (T,P)  μ °(T) for CO 2 at 225 bar at 200 K. μ (T,P)  μ °(T) = RT ln f/f°. At 225 bar f = 225 x (0.719) = 162 bar = 8.413 (JK1 mol1 ) x 200 (K) x ln (162) = 8.46 kJ mol1 d) (5 pts) Calculate μ (T,P)  μ °(T) for CO 2 at 225 bar at 200 K(for ideal gas behavior). μ (T,P)  μ °(T) = RT ln P/P°. = 8.413 (JK1 mol1 ) x 200 (K) x ln (225) = 9.01 kJ mol1 2) A solution containing 1.470 g of an unknown chlorinated benzene in 50.00 g of benzene boils at 80.60 °C at a pressure of 1 bar. The boiling point of pure benzene is 80.09 °C at 1 bar and the molar enthalpy of vaporization of pure benzene is 32.0 kJ/mol. a) (15 pts) Determine the molecular weight of the unknown chlorobenzene. ( ) ( ) ( ) * 2 ( ) ( ) ( ) ln ( ) ( ) ( ) ln 1 1 ln ( ) ( ) 1 ln / sol g B B B B sol g l B B B B g l B B B vap vap B B vap B T T T R T a T T T R T a a T T RT RT H a G T T R T R T μ μ μ μ μ μ μ μ = = + = = + = − = Δ Δ ∂ ∂ = Δ = − ∂ ∂ B G Here, Bbenzene, ggas, lliquid. Now at constant pressure and composition, we can replace the partial derivatives with regular derivatives with respect to temperature. replace the partial derivatives with regular derivatives with respect to temperature....
View
Full
Document
This test prep was uploaded on 04/13/2008 for the course CHEM 444 taught by Professor Jameslis during the Spring '08 term at University of Illinois at Urbana–Champaign.
 Spring '08
 JamesLis
 Chemistry

Click to edit the document details