Oregon State University Chemistry Exam 2 - Thermodynamics, Exams of Physical Chemistry

Download Oregon State University Chemistry Exam 2 - Thermodynamics and more Exams Physical Chemistry in PDF only on Docsity! Oregon State University, Department of Chemistry Chemistry 440 Hour exam 2 , 16 November 2005 E r n M l e y Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dE = dU(S, V , ni) = TdS - PdV + x pidni i dH(S, P, ni) = TdS + VdP + x pidni i dA(T, V, ni) = -SdT - PdV + x pidni i dG(T, P, ni) = -SdT + VdP + x pidni i H = U + P V A = U - T S Pl Vy = %h7; T2/T1 = ( V ~ / V ~ ) ~ - ' adiabatic process y = Cp/Cu A H coex problem 1 AH/ (RTa) 3 \ n 2 1. (12 pts) One mole of water vapor at a temperature Ta is heated to temperature Tb = 2T,. What are the changes in entropy and enthalpy if a) the pressure is held constant; and b) the volume is held constant? Assume water vapor behaves as an ideal gas with C, = 3R. as = ~,,IR[Tz/-~;) = c p l n 2 = 4 ~ h 2 4 a* = C = 4 R ( 2 ~ ~ -TL) = 4 R L 2. (8 pts) Two blocks of iron of equal mass are placed in thermal contact and are allowed to equilibrate. Their initial temperatures are 27°C and 127°C. Derive AH, AS. 7. (40 pts) Derive the following identities using as a starting point any of the relations given on page I. - —SAT — PAV eo. -1): as AG = —SAT =~ vaP = v@, ).= ~ Gye (ar (Fe = some function of ap (5) Tr Gh moywell traw &