19. Chemical Thermodynamics
Entropy Calculations
19. Chemical Thermodynamics
Entropy Calculations - Video Tutorials & Practice Problems
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concept
Total Entropy Formula
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example
Entropy Calculations Example
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3
concept
Entropy of Surroundings Formula
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Entropy Calculations Example
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Entropy of the System
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Entropy Calculations Example
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Problem
ProblemFor the following reaction at 27 °C, calculate ∆S°rxn, ∆Ssurr, and ∆Stot. Determine if reaction is favorable.
Fe2O3 (s) + 3 H2 (g) → 2 Fe (s) + 3 H2O (g) ∆Hrxn = 98.8 kJ
A
∆S°rxn = 0.1415 J/K, ∆Ssurr = 0.3292 J/K, ∆Stot = −0.1877 J/K, not favorable
B
∆S°rxn = 141.5 J/K, ∆Ssurr = −329.17 J/K, ∆Stot = −187.67 J/K, not favorable
C
∆S°rxn = 70.75 J/K, ∆Ssurr = 164.58 J/K, ∆Stot = −93.84 J/K, favorable
D
∆S°rxn = 283.0 J/K, ∆Ssurr = 658.34 J/K, ∆Stot = −375.34 J/K, favorable
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PRACTICE PROBLEMS AND ACTIVITIES (86)
- What is the change in entropy (∆S) when 1.32 g of propane (C3H8) at 0.100 atm pressure is compressed by a fact...
- Magnesium m#etal has ΔHfusion = 9.037 kJ>mol and ΔSfusion = 9.79 J>1K mol2. What is the melting point of...
- Calculate ∆Stotal, and determine whether the reaction is spon-taneous or nonspontaneous under standard-state c...
- Consider the vaporization of liquid water to steam at a pressure of 1 atm. (c) In what temperature range is it...
- Consider the vaporization of liquid water to steam at a pressure of 1 atm. (b) In what temperature range is it...
- The normal freezing point of n-octane 1C8H182 is -57 °C. (b) In what temperature range is the freezing of n-oc...
- (c) During a certain reversible process, the surroundings undergo an entropy change, ΔSsurr = -78 J>K. What...
- (a) What sign for ΔS do you expect when the pressure on 0.600 mol of an ideal gas at 350 K is increased isothe...
- Calculate the change in entropy that occurs in the system when 1.00 mole of isopropyl alcohol (C3H8O) melts at...
- Calculate ΔS surr at the indicated temperature for each reaction. d. ΔHrxn ° = +114 kJ; 77 K
- Given the values of ΔH° rxn, ΔSrxn ° , and T, determine ΔSuniv and predict whether or not each reaction is spo...
- Given the values of ΔH° rxn, ΔSrxn ° , and T, determine ΔSuniv and predict whether or not each reaction is spo...
- Given the values of ΔH rxn, ΔSrxn, and T, determine ΔSuniv and predict whether or not each reaction is spontan...
- Given the values of ΔH rxn, ΔSrxn, and T, determine ΔSuniv and predict whether or not each reaction is spontan...
- Calculate the change in Gibbs free energy for each of the sets of ΔH rxn, ΔSrxn, and T given in Problem 42. ...
- Using S° values from Appendix C, calculate ΔS° values for the following reactions. In each case, account for t...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Use data from Appendix IIB to calculate ΔSrxn ° for each of the reactions. In each case, try to rationalize th...
- Find ΔS° for the formation of CH2Cl2( g) from its gaseous elements in their standard states. Rationalize the s...
- What is the entropy change when the volume of 1.6 g of O2 increases from 2.5 L to 3.5 L at a constant temperat...
- Use data in Appendix C to calculate ΔH°, ΔS°, and ΔG° at 25 °C for each of the following reactions. (c) 2 P1s2...
- Using data from Appendix C, calculate ΔG° for the following reactions. Indicate whether each reaction is spont...
- For each reaction, calculate ΔHrxn ° , ΔSrxn ° , and ΔGrxn ° at 25 °C and state whether or not the reaction is...
- For each reaction, calculate ΔHrxn ° , ΔSrxn ° , and ΔGrxn ° at 25 °C and state whether or not the reaction is...
- For each reaction, calculate ΔHrxn ° , ΔSrxn ° , and ΔGrxn ° at 25 °C and state whether or not the reaction is...
- For each reaction, calculate ΔHrxn ° , ΔSrxn ° , and ΔGrxn ° at 25 °C and state whether or not the reaction is...
- For each reaction, calculate ΔHrxn ° , ΔSrxn ° , and ΔGrxn ° at 25 °C and state whether or not the reaction is...
- Consider the reaction: 2 NO( g) + O2( g) ¡ 2 NO2( g) Estimate ΔG° for this reaction at each temperature and pr...
- A certain constant-pressure reaction is barely nonspontaneous at 45 °C. The entropy change for the reaction is...
- Determine ΔG° for the reaction: Fe2O3(s) + 3 CO( g) ¡ 2 Fe(s) + 3 CO2( g) Use the following reactions with k...
- Reactions in which a substance decomposes by losing CO are called decarbonylation reactions. The decarbonylati...
- Consider the following reaction between oxides of nitrogen: NO21g2 + N2O1g2¡3 NO1g2 (c) Calculate ΔG at 1000 K...
- Consider the following reaction between oxides of nitrogen: NO21g2 + N2O1g2¡3 NO1g2 (a) Use data in Appendix C...
- Consider the following reaction between oxides of nitrogen: NO21g2 + N2O1g2¡3 NO1g2 (b) Calculate ΔG at 800 K,...
- Methanol 1CH3OH2 can be made by the controlled oxidation of methane: CH41g2 + 12O21g2¡CH3OH1g2 (b) Will ΔG for...
- Reduction of mercury(II) oxide with zinc gives metallic mercury: (b) Estimate at what temperature, if any, th...
- (a) Using data in Appendix C, estimate the temperature at which the free-energy change for the transformation...
- Elemental sulfur is formed by the reaction of zinc sulfide with oxygen: (b) At what temperature, if any, the ...
- The fuel in high-efficiency natural-gas vehicles consists primarily of methane 1CH42. (b) What is the maximum ...
- Phosphorus pentachloride forms from phosphorus trichloride and chlorine: (a) Use data in Appendix B to calcula...
- Phosphorus pentachloride forms from phosphorus trichloride and chlorine: (b) Estimate the temperature at which...
- Consider the reaction 3 CH41g2¡C3H81g2 + 2 H21g2. (a) Using data from Appendix C, calculate ΔG° at 298 K.
- The entropy change for a certain nonspontaneous reaction at 50 °C is 104 J/K. (a) Is the reaction endothermic...
- Consider a twofold expansion of 1 mol of an ideal gas at 25 °C in the isolated system shown in Figure 18.1. ...
- Given the data in Problem 18.78, calculate ∆G for the vaporization of benzene at: (a) 70 °C Predict whether be...
- Consider this reaction occurring at 298 K: N2O( g) + NO2( g) ∆ 3 NO( g) c. Can the reaction be made more spont...
- Consider this reaction occurring at 298 K: BaCO3(s) ∆ BaO(s) + CO2( g) c. Can the reaction be made more sponta...
- Living organisms use energy from the metabolism of food to create an energy-rich molecule called adenosine tri...
- Trouton's rule states that for many liquids at their normal boiling points, the standard molar entropy of vapo...
- These reactions are important in catalytic converters in automobiles. Calculate ΔG° for each at 298 K. Predict...
- Consider the following three reactions: (i) Ti1s2 + 2 Cl21g2¡TiCl41g2 (ii) C2H61g2 + 7 Cl21g2 ¡2 CCl41g2 + 6 H...
- The oxidation of glucose 1C6H12O62 in body tissue produces CO2 and H2O. In contrast, anaerobic decomposition, ...
- Use the values of of ∆G°f in Appendix B to calculate the stan-dard free-energy change for the synthesis of dic...
- The conversion of natural gas, which is mostly methane, into products that contain two or more carbon atoms, s...
- The conversion of natural gas, which is mostly methane, into products that contain two or more carbon atoms, s...
- Ethanol is manufactured in industry by the hydration of ethylene: Using the data in Appendix B, calculate ∆G°...
- At what temperatures is the following reaction, the reduction of magnetite by graphite to elemental iron, sp...
- Carbon disulfide 1CS22 is a toxic, highly flammable substance. The following thermodynamic data are available ...
- The reaction SO21g2 + 2 H2S1g2Δ3 S1s2 + 2 H2O1g2 is the basis of a suggested method for removal of SO2 from po...
- The reaction SO21g2 + 2 H2S1g2Δ3 S1s2 + 2 H2O1g2 is the basis of a suggested method for removal of SO2 from po...
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- Trouton's rule says that the ratio of the molar heat of vapor-ization of a liquid to its normal boiling point ...
- Trouton's rule says that the ratio of the molar heat of vapor-ization of a liquid to its normal boiling point ...
- The following reaction, sometimes used in the laboratory to generate small quantities of oxygen gas, has ∆G° =...
- Suppose that a reaction has ΔH = - 33 kJ and ΔS = - 58 J>K. At what temperature will it change from spontan...
- Ethyl alcohol has ΔHfusion = 5.02 kJ>mol and melts at - 114.1 °C. What is the value of ΔSfusion for ethyl a...
- Consider the unbalanced equation: (b) Use the data in Appendix B and ΔG°f for IO3 -1aq2= -128.0 kJ>mol ...
- What is the melting point of benzene in kelvin if ΔHfusion = 9.95 kJ>mol and ΔSfusion = 35.7 J> 1K mol2?
- Methanol 1CH3OH2 is made industrially in two steps from CO and H2. It is so cheap to make that it is being con...
- "Methanol 1CH3OH2 is made industrially in two steps from CO and H2. It is so cheap to make that it is being co...
- For a process to be spontaneous, the total entropy of the system and its surroundings must increase; that is Δ...
- Calculate the standard entropy change for the reaction at 25 °c
- Find ΔrS for the formation of CH3Cl(g) from its elements in their standard states. standard thermodynamic quan...
- Calculate δs∘rxn for the following reaction. The δs∘ for each species is shown below the reaction. C2H2(g) + 2...
- Calculate ∆S° for NH3(g) + HCl(g) → NH4Cl(s)
- Calculate ∆S° for C3H4(g) + 2 H2(g) → C3H8(g).
- What is the S° of HgI2(yellow) in J/mol-K?
- What is ∆G° for the reaction CaO(s) + CO2(g) → CaCO3(s)?
- What is the standard Gibbs free energy for the transformation of diamond to graphite at 298 K?