Chemistry 9th Edition

Published by Cengage Learning
ISBN 10: 1133611095
ISBN 13: 978-1-13361-109-7

Chapter 17 - Spontaneity, Entropy, and Free Energy - Exercises: 45

Answer

a. $\Delta$S$^{\circ}$= -186 J/K x mol$rxn$ b.$\Delta$S$^{\circ}$= 187 J/K x mol$rxn$ c. $\Delta$S$^{\circ}$= 348 J/K x mol$rxn$

Work Step by Step

a. 2$H_{2}$S +S$O_{2}$ -> 3 $S_{rhombic}$ + 2 $H_{2}O$ $\Delta$ S$^{\circ}$= Sum of S$^{\circ}$ (Products) - Sum of S$^{\circ}$ (Reactants) $\Delta$ S$^{\circ}$= 3 S$^{\circ}$ (S) +2 S$^{\circ}$ ($H_{2}O$)- S$^{\circ}$ (S$O_{2}$)- 2 S$^{\circ}$ ($H_{2}S$) $\Delta$ S$^{\circ}$=3 S$^{\circ}$ (32) +2 S$^{\circ}$ (189)- S$^{\circ}$ (248)- 2 S$^{\circ}$ (206) $\Delta$S$^{\circ}$= -186 J/K x mol$rxn$ b. 2S$O_{3}$ -> 2S$O_{2}$ +$O_{2}$ $\Delta$ S$^{\circ}$= Sum of S$^{\circ}$ (Products) - Sum of S$^{\circ}$ (Reactants) $\Delta$ S$^{\circ}$= 2 S$^{\circ}$ (S$O_{2}$)- S$^{\circ}$ ($O_{2}$)- 2 S$^{\circ}$ (S$O_{3}$) $\Delta$ S$^{\circ}$= 2 S$^{\circ}$ (248)- S$^{\circ}$ (205)- 2 S$^{\circ}$ (257) $\Delta$S$^{\circ}$= 187 J/K x mol$rxn$ c. $Fe_{2}$$O_{3}$ + 3$H_{2}$ -> 2 Fe + 3$H_{2}O$ $\Delta$ S$^{\circ}$= Sum of S$^{\circ}$ (Products) - Sum of S$^{\circ}$ (Reactants) $\Delta$ S$^{\circ}$= 2 S$^{\circ}$(Fe) +3 S$^{\circ}$ ($H_{2}O$)- 3 S$^{\circ}$ ($H_{2}$) - S$^{\circ}$ ($Fe_{2}$$O_{3}$) $\Delta$ S$^{\circ}$= 2 S$^{\circ}$(108) +3 S$^{\circ}$ (189)- 3 S$^{\circ}$ (115) - S$^{\circ}$ (90) $\Delta$S$^{\circ}$= 348 J/K x mol$rxn$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.