Chem 110C Spring 2010 Ames 1 Problem Set 3 (due Wed. May 5, 2010)1. [a] Calculate HandSG∆∆∆,per mol of benzene added for the process where an infinitesimal quantity of benzene is added at 298K to an ideal solution composed of 0.4 mol benzene and 0.6 mol toluene (Hint: *lnbenzenesbenzeneGµµ−=∆and TnPTGS,⎟⎟⎠⎞⎜⎜⎝⎛∆=∆δδ). [b] Calculate HandSG∆∆∆,per mol of benzene added for the process where 0.4 mol of pure benzene is mixed with 0.6 mol of pure toluene to form an ideal solution. (Hint: see ∆mixG for the standard mixing process, p977 of M&S.). 2. A natural uranium sample contains 0.7 mol percent of 235U and 99.3 mol percent of 238U. First, calculate the molar Gibbs free energy change (Gmix∆) and molar entropy change (Smix∆) for the mixing of 235U and 238U to form a natural (ideal) mixture (i.e. mol fraction of 235U (x1) is 0.007 and mol fraction of 238U (x2) is 0.993). Then calculate the entropy change (per mol of mixture) for “unmixing” 235U and 238U from a sample of natural uranium. (hint:
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