Chemistry 12.3 – Energetics of Solution Formation • The enthalpy of solution is sum of the changes in enthalpy for each step. • ΔHsolution = ΔHsolute (endo) + ΔHsolvent (endo) + ΔHmix (exo) • If the sum of the endothermic tersm is about equal in magnitude to the exothermic term, then Hsoln is about zero. The increasing entropy ipon mixing drives the solution process while the overall energy of the system remains nearly constant. • If the sum of the endothermic terms is smaller in magnitude than the exothermic term, then Hsoln is negative and solution process is exothermic. In this case, both the tendency toward lower energy and the tendency toward greater entropy drive the formation of a solution. • If the sum of the endothermic terms is greater in magnitude than the exothermic term, then Hsoln is positive and the solution process is endothermic. In this case, as long as Hsoln is not too large, the tendency toward greater entropy will still drive the formation of a solution. If, on the other hand, Hsoln is too large, a
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This note was uploaded on 04/01/2011 for the course CHEMISTRY 2400 taught by Professor Staff during the Fall '10 term at Georgia State University, Atlanta.