Slide 1 / 55 Slide 2 / 55 A reaction that is spontaneous _____. 1 - PDF document

Slide 1 / 55 Slide 2 / 55 A reaction that is spontaneous _____. 1 A reversible process is one that 2 __________. A is very rapid will proceed without outside B intervention can be reversed with no net change A is also spontaneous in the reverse in either system or surroundings C direction B happens spontaneously has an equilibrium position that lies D C is spontaneous in both directions far to the left must be carried out at low E is very slow D temperature must be carried out at high E temperature Slide 3 / 55 Slide 4 / 55 3 Which of the following 4 Of the following, only statements is true? __________ is not a state function. Processes that are spontaneous in A one direction are spontaneous in the A S opposite direction. B H Processes are spontaneous because B C q they occur at an observable rate. D E Spontaneity can depend on the C temperature. E T D All of the statements are true. Slide 5 / 55 Slide 6 / 55 The thermodynamic quantity For an isothermal process, 5 6 that expresses the degree of ΔS = __________. disorder in a system is ______. A q B q rev / T C q rev A enthalpy D Tq rev B internal energy E q + w C bond energy D entropy E heat flow

Slide 7 / 55 Slide 8 / 55 Which one of the following is The entropy of the universe is 7 8 always positive when a __________. spontaneous process occurs? A constant B continually decreasing C continually increasing A ΔS system D zero B ΔS surroundings E the same as the energy, E C ΔS universe D ΔH universe E ΔH surroundings Slide 9 / 55 Slide 10 / 55 9 The second law of 10 Which of the following thermodynamics states that statements is false? __________. The change in entropy in a system depends on the initial and final states A A ΔE = q + w of the system and the path taken ΔH° rxn = Σ nΔH° f (products) - Σ from one state to the other. B mΔH° f (reactants) Any irreversible process results in an B for any spontaneous process, the overall increase in entropy. C entropy of the universe increases The total entropy of the universe the entropy of a pure crystalline C increases in any spontaneous D substance is zero at absolute zero process. E ΔS = q rev /T at constant temperature Entropy increases with the number of D microstates of the system. Slide 11 / 55 Slide 12 / 55 Of the following, the entropy of Of the following, the entropy of 11 12 __________ is the largest. gaseous __________ is the largest at 25 o C and 1 atm. A H 2 B C 2 H 6 A HCl (l) C C 2 H 2 B HCl (s) D CH 4 C HCl (g) E C 2 H 4 D HBr (g) E HI (g)

Slide 13 / 55 Slide 14 / 55 True/False: The entropy of a True/False: The quantity of 13 14 pure crystalline substance at energy gained by a system 0 o C is zero. equals the quantity of energy gained by its surroundings. Slide 15 / 55 Slide 16 / 55 15 Which one of the following 16 ΔS is positive for __________. processes produces a decrease in the entropy of the system? A 2H 2 (g) + O 2 (g) à 2H2O(g) B 2NO(g) à N 2 O 4 (g) C CO 2 (g) à CO 2 (s) A boiling water to form steam BaF 2 (s) à Ba 2+ + 2F - (aq) D B dissolution of solid KCl in water E 2Hg(l) + O 2 (g) à 2HgO(s) mixing of two gases into one C container D freezing water to form ice E melting ice to form water Slide 17 / 55 Slide 18 / 55 Which reaction produces a ΔS is positive for _____. 18 17 decrease in the entropy of the system? A CaCO 3 (s) à CaO(s) + CO 2 (g) A CaO(s) + CO 2 (g) à CaCO 3 (s) B 2C(s) + O 2 (g) à 2CO(g) B N 2 (g) + 3H 2 (g) à 2NH 3 (g) C CO 2 (s) à CO 2 (g) C 2SO 3 (g) à 2SO 2 (g) + O 2 (g) D 2H 2 (g) + O 2 (g) à 2H 2 O(l) Ag + (aq) + Cl - (aq) à AgCl(s) D E H 2 O(l) à H 2 O(g) E H 2 O(l) à H 2 O(s)

Slide 19 / 55 Slide 20 / 55 Which reaction produces an 19 20 Which one of the following increase in the entropy of the processes produces a decrease system? of the entropy of the system? Ag + (aq) + Cl - (aq) à AgCl(s) A A dissolving sodium chloride in water B CO 2 (s) à CO 2 (g) B sublimation of naphthalene C H 2 (g) + Cl 2 (g) à 2HCl(g) C dissolving oxygen in water D N 2 (g) + 3H 2 (g) à 2NH 3 (g) D boiling of alcohol E H 2 O(l) à H 2 O(s) E explosion of nitroglycerine Slide 21 / 55 Slide 22 / 55 ΔS is negative for __________. 22 ΔS is negative for ______. 21 A 2SO 2 (g) + O 2 (g) à 2SO 3 (g) A 2H 2 O(g) à 2H 2 (g) + O 2 (g) B NH 4 Cl(s) à NH 3 (g) + HCl(g) B Mg(NO 3 ) 2 (aq) + 2NaOH(aq) à Mg(OH) 2 (s) + 2NaNO 3 (aq) PbCl 2 (s) à Pb 2+ + 2Cl - C C H 2 O(l) à H 2 O(g) D 2C(s) + 2O 2 (g) à 2CO 2 (g) D C 6 H 12 O 6 (s) à 6C(s) + 6H 2 (g) + 3O 2 (g) E H 2 O(l) à H 2 O(g) NaCl(aq) à Na + (aq) + Cl - (aq) E Slide 23 / 55 Slide 24 / 55 23 ΔS is positive for _____ . Consider a pure crystalline solid 24 that is heated from absolute zero to a temperature above the boiling point of the liquid. Which of the following processes produces the greatest increase in the entropy of the substance? A Pb(NO 3 ) 2 (aq) + 2KI(aq) à PbI 2 (s) + 2KNO 3 (aq) B 2H 2 O(g) à 2H 2 (g) + O 2 (g) A melting the solid B heating the liquid C H 2 O(g) à H 2 O(s) C heating the gas D NO(g) + O 2 (g) à NO 2 (g) D heating the solid Ag + (aq) + Cl - (aq) à AgCl(s) E E vaporizing the liquid

Slide 25 / 55 Slide 26 / 55 The value of ΔSo for the catalytic The combustion of acetylene in the 25 26 hydrogenation of acetylene to presence of excess oxygen yields ethane is _____ J/K∙ mol. carbon dioxide and water is shown below. The value of ΔSo for this C 2 H 2 (g) + H 2 (g) à C 2 H 4 (g) reaction is __________ J/K∙ mol. A +18.6 2C 2 H 2 (g) + 5O 2 à 4CO 2 (g) + 2H 2 O(l) B +550.8 A +689.3 C +112.0 B +122.3 D -112.0 C +432.4 E -18.6 D -122.3 E -432.4 Slide 27 / 55 Slide 28 / 55 What is the value of ΔS°, in J/K∙ mol, for 28 The value of ΔSo for the oxidation 27 this reaction: the combustion of ethene of carbon to carbon dioxide? in the presence of excess oxygen C(s, graphite) + O2(g) à CO2(g) yielding carbon dioxide and water: C2H4(g) + 3O2(g) à 2CO2(g) + 2H2O(l) A +424.3 B +205.0 A -267.4 C -205.0 B -140.9 D -2.9 C -347.6 E +2.9 D +347.6 E +140.9 Slide 29 / 55 Slide 30 / 55 The combustion of ethane in the 29 The value of ΔSo for the oxidation of 30 presence of excess oxygen yields solid elemental sulfur to gaseous sulfur carbon dioxide and water. The value of trioxide, as shown below, is __ J/K∙ mol. ΔSo for this reaction is ___ J/K∙ mol. 2S(s, rhombic) + 3O 2 (g) à 2SO 3 (g) 2C 2 H 6 (g) + 7O 2 (g) à 4CO 2 (g) + 6H 2 O(l) A +19.3 B -19.3 A +718.0 C +493.1 B -620.1 D -166.4 C -718.0 E -493.1 D -151.0 E +151.0

Slide 31 / 55 Slide 32 / 55 The value of ΔSo for the formation of The value of ΔSo for the decomposition 32 31 POCl3 from its constituent elements, of gaseous sulfur trioxide to solid elemental sulfur and gaseous oxygen, as shown below, is ___ J/K∙ mol. as shown below, is ___ J/K∙ mol. P 2 (g) + O 2 (g) + 3Cl 2 (g) à 2POCl 3 (g) 2SO 3 (g) à 2S(s, rhombic) + 3O 2 (g) A -442.0 A +19.3 B +771.0 B -19.3 C -321.0 C +493.1 D -771.0 D +166.4 E -493.1 E +321.0 Slide 33 / 55 Slide 34 / 55 The value of ΔSo for the 33 The value of ΔS o for the formation 34 decomposition of POCl3 into its of calcium chloride from its constituent elements, as shown constituent elements, as shown below is __________ J/K∙ mol. below, is ___ J/K∙ mol. 2POCl 3 (g) à P 2 (g) + O 2 (g) + 3Cl 2 (g) Ca(s) + Cl 2 (g) à CaCl 2 (s) A -104.6 A +771.0 B +104.6 B +442.0 C +369.0 C -321.0 D -159.8 D -771.0 E +159.8 E +321.0 Slide 35 / 55 Slide 36 / 55 The standard Gibbs free energy of The standard Gibbs free energy of 35 36 formation of __________ is zero. formation of __________ is zero. (I) H 2 O(l) (II) Na(s) (III) H 2 (g) (I) H 2 O(l) (II) O(g) (III) H 2 (g) A A I only I only B II only B II only C III only C III only D II and III D II and III E I, II, and III E I, II, and III

Slide 37 / 55 Slide 38 / 55 The value of ΔG o at 25 o C for the The standard Gibbs free energy of 38 37 decomposition of gaseous sulfur formation of __________ is zero. trioxide to solid elemental sulfur and gaseous oxygen, as shown (I) Al (s) (II) Br 2 (l) (III) Hg (l) below, is __________ kJ/mol. 2SO 3 (g) à 2S(s, rhombic) + 3O 2 (g) A I only B II only A +740.8 C III only B -370.4 D II and III C +370.4 E I, II, and III D -740.8 E +185.2 Slide 39 / 55 Slide 40 / 55 The value of ΔG o at 25 o C for 39 The value of ΔG o at 25 o C for 40 the decomposition of gaseous the formation of POCl3 from its sulfur dioxide to solid elemental constituent elements, as sulfur and gaseous oxygen,, as shown below, is ______ kJ/mol. shown below, is ______ kJ/mol. P 2 (g) + O 2 (g) + 3Cl 2 (g) à 2POCl 3 (g) SO 2 (g) à S(s, rhombic) + O 2 (g) A -1,108.7 B +1,108.7 A +395.2 C -606.2 B +269.9 D +606.2 C -269.9 E -1,005 D +300.4 E -300.4 Slide 41 / 55 Slide 42 / 55 The value of ΔG o at 25 o C for the The value of ΔG o at 373 K for the 41 42 formation of phosphorous trichloride oxidation of solid elemental sulfur from its constituent elements, as to gaseous sulfur dioxide, as shown below, is ____ kJ/mol. shown below, is ______ kJ/mol. At 298 K, ΔH o for this reaction is -269.9 P 2 (g) + 3Cl 2 (g) à 2PCl 3 (g) kJ/mol, and ΔS o is +11.6 J/K. A -539.2 B +539.2 S(s, rhombic) + O 2 (g) à SO 2 (g) C -642.9 D +642.9 A -300.4 E -373.3 B +300.4 C -4,597 D +4,597 E -274.2