Concept explainers
(a)
Interpretation: It is given that, sulfur undergoes a phase change from the rhombic crystal structure to the monoclinic crystal form at temperatures above
Concept introduction: Entropy is the measure of degree of disorder or randomness. The value of
(b)
Interpretation: It is given that, sulfur undergoes a phase change from the rhombic crystal structure to the monoclinic crystal form at temperatures above
Concept introduction: Entropy is the measure of degree of disorder or randomness. The value of
Want to see the full answer?
Check out a sample textbook solutionChapter 16 Solutions
Chemistry: An Atoms First Approach
- Solid NH4NO3 is placed in a beaker containing water at 25 C. When the solid has completely dissolved, the temperature of the solution is 23.5 C. (a) Was the process exothermic or endothermic? (b) Was the process spontaneous? (c) Did the entropy of the system increase? (d) Did the entropy of the universe increase?arrow_forwardDefine the following: a. spontaneous process b. entropy c. positional probability d. system e. surroundings f. universearrow_forwardA key component in many chemical engineering designs is the separation of mixtures of chemicals. (a) What happens to the entropy of the system when a chemical mixture is separated? (b) Are designs for chemical separation more likely to rely on spontaneous or nonspontaneous processes?arrow_forward
- How does the second law of thermodynamics explain a spontaneous change in a system that becomes more ordered when that process is exothermic?arrow_forwardThe melting point for carbon diselenide (CSe2) is 46C. At a temperature of 75C, predict the signs for Ssurr and Swater for the following process: CSe2(l) CSe2(s).arrow_forwardGiven the values of H and S, which of the following changes will be spontaneous at constant T and p? a. H = + 25 kJ, S = + 5.0 J/K, T = 300. K b. H = + 25 kJ, S = + 100. J/K, T = 300. K c. H = 10. kJ, S = + 5.0 J/K, T= 298 K d. H = 10.kJ, S =40.J/K, T = 200.Karrow_forward
- For the reaction at 298 K, 2NO2(g)N2O4(g) the values of H and S are 58.03 kJ and 176.6 J/K, respectively. What is the value of G at 298 K? Assuming that H and S do not depend on temperature, at what temperature is G = 0? Is G negative above or below this temperature?arrow_forwardSome water is placed in a coffee-cup calorimeter. When 1.0 g of an ionic solid is added, the temperature of the solution increases from 21.5C to 24.2C as the solid dissolves. For the dissolving process, what are the signs for Ssys, Ssurr, and Suniv?arrow_forwardThermodynamics provides a way to interpret everyday occurrences. If you live in northern climates, one common experience is that during early winter, snow falls but then melts when it hits the ground. Both the formation and the melting happen spontaneously. How can thermodynamics explain both of these seemingly opposed events?arrow_forward
- When solid sodium acetate crystallizes from a supersaturated solution, can you accurately predict the sign of H for the crystallization? Why or why not?arrow_forwardAt what temperatures will the following processes be spontaneous? a. H = 18 kJ and S = 60. J/K b. H = +18 kJ and S = + 60. J/K c. H = +18 kJ and S = 60. J/K d. H = 18 kJ and S = +60. J/Karrow_forwardThrough photosynthesis, plants build molecules of sugar containing several carbon atoms from carbon dioxide. In the process, entropy is decreased. The reaction of CO2with formic acid to form oxalic acid provides a simple example of a reaction in which the number of carbon atoms in a compound increases: CO2(aq)+HCOOH(aq)H2C2O4(aq) (a) Calculate the standard entropy change for this reaction and discuss the sign of S . (b) How do plants carry out reactions that increase the number of carbon atoms in a sugar, given the changes in entropy for reactions like this?arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning
- General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning