Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A B C observations The reverse of this reaction is always spontaneous but proceeds slower at temperatures below -26. °C. This reaction is spontaneous except above -42. °℃. This reaction is endothermic. AH is conclusions As is ΔΗ is AS is ΔΗ is AS is (pick one) (pick one) (pick one) (pick one) (pick one) (pick one)

Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction A B C observations The reverse of this reaction is always spontaneous but proceeds slower at temperatures below -26. °C. This reaction is spontaneous except above -42. °℃. This reaction is endothermic. AH is conclusions As is ΔΗ is AS is ΔΗ is AS is (pick one) (pick one) (pick one) (pick one) (pick one) (pick one)

Chemistry for Engineering Students

4th Edition

ISBN:9781337398909

Author:Lawrence S. Brown, Tom Holme

Publisher:Lawrence S. Brown, Tom Holme

Chapter10: Entropy And The Second Law Of Thermodynamics

Section: Chapter Questions

Problem 10.84PAE: Methane can be produced from CO and H2.The process might be done in two steps, as shown below, with...

See similar textbooks

Similar questions

For the process A(l) A(g), which direction is favored by changes in energy probability? Positional probability? Explain your answers. If you wanted to favor the process as written, would you raise or lower the temperature of the system? Explain.
What is the second law of thermodynamics? For any process, there are four possible sign combinations for Ssys and Ssurr. Which sign combination(s) always give a spontaneous process? Which sign combination(s) always give a non-spontaneous process? Which sign combination(s) may or may not give a spontaneous process?
The enthalpy of vaporization of ethanol is 38.7 kJ/mol at its boiling point (78C). Determine Ssys, Ssurr, and Suniv when 1.00 mole of ethanol is vaporized at 78C and 1.00 atm.
What is the sign of the standard Gibbs free-energy change at low temperatures and at high temperatures for the formation of hydrogen sulfide from the elements? H2(g)+18S8(s)H2S(g)
Use data from Appendix D to calculate the standardentropy change at 25°C for the reaction CH3COOH(g)+NH3(g)CH3NH2(g)+CO2(g)+H2(g) Suppose that 1.00 mol each of solid acetamide, CH3CONH2(s), and water, H2O(l), react to give thesame products. Will the standard entropy change belarger or smaller than that calculated for the reactionin part (a)?
For the reaction NO(g)+NO2(g)N2O3(g) , use tabulated thermodynamic data to calculate H and S. Then use those values to answer the following questions. (a) Is this reaction spontaneous at 25°C? Explain your answer. (b) If the reaction is not spontaneous at 25°C, will it become spontaneous at higher temperatures or lower temperatures? (c) To show that your prediction is accurate, choose a temperature that corresponds to your prediction in part (b) and calculate G . (Assume that both enthalpy and entropy are independent of temperature.)
The standard molar entropy of iodine vapor, I2(g), is 260.7 J Kl mol-1 and the standard molar enthalpy of formation is 62.4 kJ/mol. a) Calculate the entropy change for vaporization of 1 mol of solid iodine (use data from Table 16.1 or Appendix J). b) Calculate the enthalpy change for sublimation of iodine. c) Assuming that rSdoes not change with temperature, estimate the temperature at which iodine would sublime (change directly from solid to gas).
Thermite reactions have been used for welding metal parts such as railway rails and in metal refining. One such thermite reaction is Fe2O3(s)+2Al(s)Al2O3(s)+2Fe(s). Is the reaction spontaneous at room temperature under standard conditions? During the reaction, the surroundings absorb 851.8 kJ/mol of heat.
The biological oxidation of ethanol, C2H5OH, is also a source of Gibbs free energy. (a) Does the oxidation of 1 g ethanol give more or lessenergy than the oxidation of 1 g glucose?(Hint:Writethe balanced equation for the production of carbondioxide and water from ethanol and oxygen, and useAppendix J.) (b) Comment on potential problems of replacing glucosewith ethanol in your diet.
Many plastic materials are organic polymers that contain carbon and hydrogen. The oxidation of these plastics in air to farm carbon dioxide and water is a spontaneous process; however, plastic materials tend to persist in the environment. Explain.
A 220-ft3 sample of gas at standard temperature and pressure is compressed into a cylinder, where it exerts pressure of 2000 psi. Calculate the work (in J) performed when this gas expands isothermally against an opposing pressure of 1.0 atm. (The amount of work that can be done is equivalent to the destructive force of about 1/4 lb of dynamite, giving you an idea of how potentially destructive compressed gas cylinders can be if improperly handled!)
When 1.000 g of ethylene glycol, C2H6O2, is burned at 25C and 1.00 atmosphere pressure, H2O(l) and CO2(g) are formed with the evolution of 19.18 kJ of heat. a Calculate the molar enthalpy of formation of ethylene glycol. (It will be necessary to use data from Appendix C.) b Gf of ethylene glycol is 322.5 kJ/mol. What is G for the combustion of 1 mol ethylene glycol? c What is S for the combustion of 1 mol ethylene glycol?