Chemistry Exam: Thermodynamics and Equations of State, Exams of Physical Chemistry

Download Chemistry Exam: Thermodynamics and Equations of State and more Exams Physical Chemistry in PDF only on Docsity! Chemistry 440 Hour exam .... Ex ......................... Alu? GY... . . ........ Department of Chemistry, Oregon State University 19 October 2005 R = 8.3 J / ( K . mol) = 0.082 L . atm/(K - mol) 1 bar = lo5 Pa 1.01 bar = 1.0 atm AE = qby + w m = qb - way = qb - 1 pmtdv H = E+PV cv = (g)v d H P = (=) P CP PIV;' = p2V;, T = T for an adiabatic process; y G - cv 1. Provide an equation or two and define terms. (a) (4 pts) State the First Law of Thermodynamics as it applies to the universe and to a system (two equations). E- d-thc U ~ \ W I i s a n p r d A~,,,;= o whwPcls * ewqy OF* 8 y s h m h cbwd ~f M - f l o w s +V S \ ~ Q ~ ~ M O C rF% vskrn d a P o w ~ L (b) (4 pts) Define an open system and an isolated system. AE=9%+VIcm (c) (2 pts) Define the inversion temperature by an equation. 2. (10 pts) What decrease in temperature and increase in pressure are needed to cause the volume of liquid water to drop by O.Ol%? a p = 2 x ~ o - ~ / K , KT = 5 x 1 0 - ~ / b a r , p ~ ~ = O.SOK/bar. 1 6. (10 pts) Consider the function G = H - TS. (a) Construct the total derivative of G to show that dG(T, P) obeys dG(T, P) = -SdT + VdP (5) Hint: the combined first and second laws of thermodynamics are expressed by the dif- ferential equation dE(S, V) = TdS - PdV (6) d G = d l ~ - ~ ) = = d & + ~ v -TS) -rds -&T (b) Using the equation for dG, complete the following 7. (15 pts) Shown on the figure are three isotherms for a fluid. (a) Label as Thot 7 T c o ~ and Tcritical. (b) Select the points of phase coexistence on this graphs (points a, b, c, d, e . & C (c) What conditions does the pressure satisfy at point c? Di IS o n 9 01%- P- pL%?L)T = @p@j, = o @ & cn+td I t , c. AE '1 j inal pf inal qby,", T. . . p. nstrnl . . Won 8. (20 pts) One mole of an ideal gas at a temperature T is expanded from a volume V to a volume 8V. Calculate the quantities indicated in the table for the following processes: (a) an isothermal, reversible expansion; (b) a reversible adiabatic expansion in which C, = ;R; Cp = $R . PIVI - Rvr > c- r , ~ , - - - Ti- I \ - 1 r; pi 4 8 37. -- - a / - T; V p