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Chemistry Ch.17
Question | Answer |
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1) Which of the following statements is TRUE? | A) There is a "heat tax" for every energy transaction. |
2) In which of the following processes does the molecules become more orderly? | A) water freezing |
3) Identify the change in state that does not have an increase in entropy. | A) water freezing |
4) Which of the following processes have a ΔS > 0? | C) CH4(g) + H2O (g) → CO(g) + 3 H2(g) |
5) Which of the following processes have a ΔS > 0? | D) sodium chloride dissolves in pure water |
6) Which of the following processes have a ΔS < 0? | E) All of the above processes have a ΔS < 0. |
7) Which of the following processes shows a decrease in entropy of the system? | A) 2 NO(g) + O2(g) → 2 NO2(g) |
8) Which of the following statements is TRUE? | B) Endothermic processes decrease the entropy of the surroundings, at constant T and P. |
9) What is the sign of ΔSuniv for a biological system? | A) positive |
13) Which of the following relationships is correct at constant T and P? | A) ΔG is proportional to -ΔSuniv |
14) Consider a reaction that has a positive ΔH and a positive ΔS. Which of the following statements is TRUE? | A) This reaction will be spontaneous only at high temperatures. |
15) Consider a reaction that has a positive ΔH and a positive ΔS. Which of the following statements is TRUE? | D) This reaction will be nonspontaneous only at low temperatures. |
16) Consider a reaction that has a negative ΔH and a positive ΔS. Which of the following statements is TRUE? | B) This reaction will be spontaneous at all temperatures. |
17) Consider a reaction that has a positive ΔH and a negative ΔS. Which of the following statements is TRUE? | C) This reaction will be nonspontaneous at all temperatures. |
18) Consider a reaction that has a negative ΔH and a negative ΔS. Which of the following statements is TRUE? | D) This reaction will be nonspontaneous only at high temperatures. |
19) Consider a reaction that has a negative ΔH and a negative ΔS. Which of the following statements is TRUE? | A) This reaction will be spontaneous only at low temperatures. |
20) For the following example, identify the following. 2 N2O (g) → 2 N2(g) + O2(g) | C) a negative ΔH and a positive ΔS |
21) For the following example, identify the following. 3O2 (g) → 2O3(g) | B) a positive ΔH and a negative ΔS |
22) For the following example, identify the following. H2O (l) → H2O(g) | D) a positive ΔH and a positive ΔS |
23) For the following example, identify the following. H2O (l) → H2O(s) | A) a negative ΔH and a negative ΔS |
27) Which of the following statements is TRUE? | A) Entropy is an extensive property. |
28) Identify the statement that is FALSE. | C) Free atoms have greater entropy than molecules. |
34) Place the following in order of increasing standard molar entropy. H2O (l) H2O (g) H2O (s) | B) H2O (s) < H2O (l) < H2O (g) |
35) Place the following in order of decreasing standard molar entropy. NaCl(s) Na3PO4 (aq) NaCl (aq) | C) Na3PO4 (aq) > NaCl (aq) > NaCl(s) |
39) Identify the compound that is NOT an allotrope of carbon. | B) dry ice |
45) Identify the compound with the lowest standard free energy of formation. | A) NaCl(s) |
46) Identify the compound with the highest standard free energy of formation. | D) O3(g) |
47) Identify the compound with the standard free energy of formation equal to zero. | B) N2(g) |
48) What can change the direction of a reversible reaction? | E) all of the above |
49) Give the name of the reaction that achieves the theoretical limits with respect to free energy in thermodynamics. | A) reversible reaction |
50) Give the name of the reaction that does not achieve the theoretical limits with respect to free energy in thermodynamics. | E) irreversible reaction |
74) Which of the following is NOT true for ΔGrxn? | A) If ΔG°rxn > 0, the reaction is spontaneous in the forward direction. |
75) Choose the statement below that is TRUE. | D) ΔGrxn = 0 at equilibrium. |
76) What is true if ln K is negative? | D) ΔGorxn is positive and the reaction is spontaneous in the reverse direction. |
77) What is true if ln K is positive? | B) ΔGorxn is negative and the reaction is spontaneous in the forward direction. |
78) What is true if ln K is zero? | E) ΔGorxn is zero and the reaction is at equilibrium. |
79) Which of the following reactions will have the largest equilibrium constant (K) at 298 K? | B) 2 Hg(g) + O2(g) → 2 HgO(s) ΔG° = -180.8 kJ |
5) For a given reaction, ΔH = + 35.5 kJ/mol and ΔS = + 83.6 J/Kmol. The reaction is spontaneous __________. Assume that ΔH and ΔS do not vary with temperature. | B) at T > 425 K |
6) Under which of the following conditions would one mole of He have the highest entropy, S? | D) 127°C and 25 L |
1) Q = K | D) equilibrium |
2) Q < K | G) DG < 0 |
3) Q > K | B) ΔG > 0 |
4) Q = 1 | A) standard state |
5) Q > 1 | C) ΔG > ΔG° |
6) Q < 1 | E) ΔG < ΔG° |
71) Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 3 O2(g) → 2 O3(g) ΔG° = +326 kJ P(O2) = 0.41 atm, P(O3) = 5.2 atm | A) +341 kJ |
72) Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g) + O2(g) → 2 HgO(s) ΔG° = -180.8 kJ P(Hg) = 0.025 atm, P(O2) = 0.037 atm | B) -154.4 kJ |