Question

Use the standard molar entropies to calculate Delta Sdegree_rtimes n for the following reactions: Ag^++(aq) + Cl^-(aq) rightarrow AgCl(s) CH_3CH_2CH_3(g) + 5 O_2(g) rightarrow 3 CO_2(g) + 4 H_2O(l) NH_3(g) + HCl(g) rightarrow NH_4Cl(s)

Answer 1

delta S of the reaction = delta S of the products - delta s of the reactants

Part A

delta S of the reaction = [96.2 J/mol K] - [72.7 J /mol K + 56.5 j/mol K]

= -33 J/mol K

Part B

delta S of the reaction = [3 (213.6 J /mol -K) + 4(4 69.9 J / mol-K) ] - [269.9 J / mol K +205.0 J / mol K]

delta S of the reaction = [640.8 J /mol K + 1879.6 J / mol K] - [474.9 J/mol K]

delta S of the reaction = 2045.5 J/mol K

Part C

delta S of the reaction = [94.6 J/mol K ] - [192.3 J/mol K + 186.8 J/mol K]

delta S = -284.5 J/mol K