Test Bank Answers Thermochemistry Ch.5 2nd Edition

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Chapter 05: Thermochemistry

1. If ΔH = -54.74 kJ for a chemical reaction, that reaction _____________. (Outcome # 1,2) DOK 1
2. is exothermic
3. is endothermic
4. cannot occur
5. A _____ is an experimental set-up that can be used to measure the heat of a chemical reaction or a physical change and determine the specific heat capacity of a substance. (Outcome # 10) (DOK 1)
6. manometer
7. thermometer
8. calorimeter
9. The following can be used to measure the heat of combustion for an unknown sample? (Outcome # 10) (DOK 2)
10. bomb manometer
11. bomb calorimeter
12. coffee-cup calorimeter
13. Coffee-cup calorimetry is carried out at _____. (Outcome # 10) (DOK 1)
14. constant-volume
15. constant-pressure
16. constant-mass
17. Bomb calorimetry is carried out at _____. (Outcome # 10) (DOK 1)
18. constant-volume
19. constant-pressure
20. constant-mass
21. You are asked to design an experiment to measure the enthalpy of a given reaction. The reaction needs to be at atmospheric pressure so which of the following techniques would be ideal for this experiment? (Outcome # 10) (DOK 3)
22. bomb manometry
23. bomb calorimetry
24. coffee-cup calorimetry
25. Your task is to measure the amount of energy evolved during the combustion of some hydrocarbon. Which of the following would be the ideal technique for this experiment? (Outcome # 10) (DOK 3)
26. coffee-cup calorimetry
27. bomb calorimetry
28. bomb manometry
29. 100 mL of a 0.300 M solution of AgNO₃ reacts with 100 mL of a 0.300 M solution of HCl in a coffee-cup calorimeter and the temperature rises from 21.80 °C to 23.20 °C. Assuming the density and specific heat of the resulting solution is 1.00 g/mL and 4.18 J/g ∙ °C, respectfully, what is the ΔH°_rxn? (Outcome # 11) (DOK 3)
30. -39.0 kJ/mol
31. +39.0 kJ/mol
32. +1.17 kJ/mol
33. Given the ∆H°_f, calculate the ∆H°_rxn for the formation of diamond from graphite. (Outcome # 11) (DOK 2)

∆H°_f (C, graphite) = 0 kJ/mol

∆H°_f (C, diamond) = 2 kJ/mol

1. 0 kJ/mol
2. +2 kJ/mol
3. -2 kJ/mol
4. Calculate the ∆H°_rxn for the combustion of methane using the given ∆H°_f. (Outcome # 11) (DOK 3)

∆H°_f, methane(g) = -74.60 kJ/mol

∆H°_f, water(l) = -285.8 kJ/mol

∆H°_f, carbon dioxide(g) = -393.5 kJ/mol

1. -1.04 x 10⁺³ kJ/mol
2. -890.5 kJ/mol
3. 890.5 kJ/mol
4. A drop in water temperature is observed when 0.873 g of ammonium nitrate is added. The enthalpy change for this reaction is +0.280 kJ. Which of the statements is accurate? (Outcome # 11) (DOK 3)
5. The ∆H°_soln for ammonium nitrate is +25.7 kJ/mol so this is an endothermic process where energy in the form of heat is absorbed from the surroundings.
6. The ∆H°_soln for ammonium nitrate is -25.7 kJ/mol so this is an exothermic process where energy in the form of heat is released into the surroundings.
7. The ∆H°_soln for ammonium nitrate is +25.7 kJ/mol so this is an endothermic process where energy in the form of heat is released into the surroundings.
8. An increase in water temperature is observed when 1.97 g of NaOH is added. The enthalpy change for this reaction is -2.19 kJ. Which of the statements is accurate? (Outcome # 11) (DOK 3) (Paired item 1)
9. The ∆H°_soln for NaOH is +44.5 kJ/mol so this is an endothermic process where energy in the form of heat is absorbed from the surroundings.
10. The ∆H°_soln for NaOH is -44.5 kJ/mol so this is an exothermic process where energy in the form of heat is released into the surroundings.
11. The ∆H°_soln for NaOH is -44.5 kJ/mol so this is an exothermic process where energy in the form of heat is absorbed from the surroundings.
12. If ∆H = -73.54 kJ for a chemical reaction, that reaction _____________. (Outcome # 1,5,9) (DOK 2)
13. is exothermic
14. is endothermic
15. cannot occur
16. A chemical reaction that gives off energy in the form of heat is considered _____. (Outcome # 5) (DOK 2)
17. exothermic
18. endothermic
19. exergonic
20. A chemical reaction that absorbs energy in the form of heat is considered _____. (Outcome # 5) (DOK 2) (Paired item 1)
21. exothermic
22. endothermic
23. exergonic
24. A reaction requires a sample to be heated using a water bath near boiling temperature. Which statement below would be accurate? (Outcome # 5) (DOK 3)
25. Boiling water is an endothermic process and to break apart the intermolecular forces that hold together the water molecules requires -40.7 kJ of energy.
26. Boiling water is an exothermic process and to break apart the intermolecular forces that hold together the water molecules requires +40.7 kJ of energy.
27. Boiling water is an endothermic process and to break apart the intermolecular forces that hold together the water molecules requires +40.7 kJ of energy.
28. A reaction where the products are lower in energy than the reactants is an example of an _____. (Outcome # 6) (DOK 1)
29. endothermic process
30. exothermic process
31. endergonic process
32. A reaction where the products are higher in energy than the reactants is an example of an _____. (Outcome # 6) (DOK 1)
33. endothermic process
34. exothermic process
35. exergonic process
36. An _____ reaction results when the energy required to break bonds in the reactants is greater than the energy released by the formation of products. (Outcome # 3) (DOK 1)
37. exergonic
38. endothermic
39. exothermic
40. An _____ reaction results when the energy released by the formation of products is greater than the energy required to break the bonds in the reactants. (Outcome # 3) (DOK 1)
41. exergonic
42. endothermic
43. exothermic