[AG (Ag ) + AGF(CH)]- [AG;(AgCI) ] =[(1 mol)(77.1 kJ/mol) + (1 mol)(- 131.3 kJ/mol)]-[(1 mol)(- 109.8 kJ/mol) ] %3D = 55.7 kJ 55700 J *The positive value of AG° indicates that the reaction is non-spontaneous at 25°C. This means that the reverse reaction is more spontaneous. Activity 3 Problem Solving Directions: Calculate the AH, AS", AG°. Show your complete solution. 1. Determine the spontaneity of the dissociation of ammonium nitrate (NH,NO3), the compound used in cold packs. Interpret the values obtained from the calculations. The temperature is 298.15 K. NH,NO3 () NH, (a9) + NO3 (aq) Substance NHNO3 (9) NO3 (ag). -132.5 -207.4 AH° (kJ/mol) S (J/mol-K) -365.6 151.1 113.0 146.4 a. Calculate the AH", Page | 5

[AG (Ag ) + AGF(CH)]- [AG;(AgCI) ] =[(1 mol)(77.1 kJ/mol) + (1 mol)(- 131.3 kJ/mol)]-[(1 mol)(- 109.8 kJ/mol) ] %3D = 55.7 kJ 55700 J *The positive value of AG° indicates that the reaction is non-spontaneous at 25°C. This means that the reverse reaction is more spontaneous. Activity 3 Problem Solving Directions: Calculate the AH, AS", AG°. Show your complete solution. 1. Determine the spontaneity of the dissociation of ammonium nitrate (NH,NO3), the compound used in cold packs. Interpret the values obtained from the calculations. The temperature is 298.15 K. NH,NO3 () NH, (a9) + NO3 (aq) Substance NHNO3 (9) NO3 (ag). -132.5 -207.4 AH° (kJ/mol) S (J/mol-K) -365.6 151.1 113.0 146.4 a. Calculate the AH", Page | 5

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter16: Thermodynamics: Directionality Of Chemical Reactions

Section: Chapter Questions

Problem 53QRT

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Similar questions

9.96 Most first aid "cold packs" are based on the endothermic dissolution of ammonium nitrate in water: NH4NO3(s)NH4+(aq)+NO3(aq) H= 25.69 kJ A particular cold pack contains 50.0 g of NH4NO3 and 125.0 g of water. When the pack is squeezed, the NH4NO3dissolves in the water. If the pack and its contents are initially at 24.0°C, what is the lowest temperature that this bag could reach? (Assume that the ammonium nitrate solution has a specific heat of 4.25J g-l K-l, and that the heat capacity of the bag itself is small enough to be neglected.)
Using values of fH and S, calculate rG for each of the following reactions at 25 C. (a) 2 Na(s) + 2 H2O() 2 NaOH(aq) + H2(g) (b) 6 C(graphite) + 3 H2(g) C6H6() Which of these reactions is (are) predicted to be product-favored at equilibrium? Are the reactions enthalpy- or entropy-driven?
What is a spontaneous reaction?
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