Two Examples
In the introduction to this tutorial you encountered two reactions that were endothermic yet still product-favored. The second reaction was between barium hydroxide and ammonium chloride:
Ba(OH)2 8H2O (s) +
2 NH4Cl (s) BaCl2 2H2O
(s) + 2 NH3 (aq) + 8 H2O (l)
Three moles of two solids react to form one mole of a solid, eight moles of liquid, and two moles of an aqueous solution. Using Patterns in the Entropies of Substances, would you expect the entropy change of this reaction to be positive or negative?
Calculate DSuniv for the reaction and verify that it is, indeed, positive, making the reaction product-favored.
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