27 Co Ni Fe Cu Ag Ru Pd Rh Pt Os Ir 192.

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1 UW VERSIONA CHEM152,Sp11 1A 1 H Li Na A 4 Be UsefulConstants: R=8.314J/mol.K= liter.atm/mol.K Avogadro snumber:n a =6.022x10 23 molecules/mol Boltzmann sconstant:k=1.38x10 23 J/K 101.3J=1liter.atm C V =3/2R C P =5/2R 12 Mg B 4B 5B 6B 7B 8B 8B 8B 1B 2B 3A 4A 5A 6A 7A 5 B Al C Si N P O S F Cl A 2 He Ne Ar K Rb Cs Fr (223) 20 Ca Sr Ba Ra Sc Y La Ac (227) 22 Ti Zr Hf V Nb Ta Cr Mo W Mn Tc (98) 75 Re Fe Ru Os Co Rh Ir Ni Pd Pt Cu Ag Au Zn Cd Hg Ga In Tl Ge Sn Pb As Sb Bi Se Te Po (209) 35 Br I At (210) 36 Kr Xe Rn (222) EXAM1 VERSIONA Page1of11

2 UW VERSIONA CHEM152,Sp11 SCRATCHPAPER EXAM1 VERSIONA Page2of11

3 UW VERSIONA CHEM152,Sp11 SCRATCHPAPER EXAM1 VERSIONA Page3of11

4 UW VERSIONA CHEM152,Sp11 CHEM152 EXAM1 VERSIONA Instructor: Dr.ColleenCraig NOLAPTOPSORTABLETSALLOWED Date: Wednesday,April27 Time: 11:30 12:20am Location: KNE130 ONLYCALCULATORSMAYBEUSEDASCALCULATORS (youmaynotuseyourcellularphoneasacalculator) NOHEADPHONESALLOWED(EARPLUGSAREOK) NOHATSWITHBRIMSALLOWED!!!!PLEASEREADTHIS!!!! IndicateallofthefollowingonyourScantronformorfivepointswillbe deductedfromyourscore: FirstName,LastName,StudentNumber,Section,ExamVersion YOURFULLNAME: firstname lastname YOURTA/SECTION: TA sname discussionsection YOURSEATNUMBER: Question PointsPossible Score ScantronInfo? 5 TOTAL 100 EXAM1 VERSIONA Page4of11

5 UW VERSIONA CHEM152,Sp11 40POINTSTOTAL Thereisonlyonecorrectanswertoeach multiple choicequestion 1. A gas releases 4.4 J of heat and then performs 11.4 J of work. What is the change in internal energy of the gas? A) 7.0 J B) J C) 15.8 J D) 7.0 J 2. Two metals of equal mass with different heat capacities are subjected to the same amount of heat. Which undergoes the smaller change in temperature? A) The metal with the lower heat capacity. B) Both undergo the same change in temperature. C) The metal with the higher heat capacity. D) To determine this, you need to know the initial temperatures of the metals. 3. Elemental sulfur exists in two crystalline forms, rhombic and monoclinic. From the following data, calculate the temperature at which monoclinic sulfur and rhombic sulfur are in equilibrium. S (rhombic) S (monoclinic) A) 450 K B) +450 K C) +210 K D) 210 K ΔH f (kj/mol) S (J/K mol) S (rhombic) S (monoclinic) The standard free energy of formation of AgCl(s) is 110. kj/mol. Calculate ΔG for the reaction A) 110. kj B) 110. kj C) 220. kj D) 220. kj 2 AgCl(s) 2 Ag(s) + Cl 2 (g) EXAM1 VERSIONA Page5of11

6 UW VERSIONA CHEM152,Sp11 5. A 100-mL sample of water is placed in a coffee cup calorimeter. When 1.0 g of an ionic solid is added, the temperature decreases from 21.5 C to 20.8 C as the solid dissolves. Which of the following is true for the dissolving of the solid? A) ΔS sys < 0 B) ΔS surr > 0 C) ΔS univ > 0 D) ΔH < 0 6. At constant pressure, the reaction 2 NO 2 (g) N 2 O 4 (g) is exothermic. The reaction (as written) is A) spontaneous at low temperatures but not at high temperatures. B) spontaneous at high temperatures but not at low temperatures. C) never spontaneous. D) always spontaneous. 7. Consider the reaction 2 N 2 O 5 (g) 4 NO 2 (g) + O 2 (g) At 25 C, ΔH o = 110. kj and ΔS o = 454 J/K. In a certain experiment, the reaction is allowed to proceed until all substances involved have reached their equilibrium concentrations. What is ΔG for this reaction at equilibrium? A) 11.2 kj B) 98.7 kj C) 0 D) 25.2 kj 8. The reaction 2 H 2 O(g) 2 H 2 (g) + O 2 (g) has a positive value of ΔG. Which of the following statements must be true? A) The equilibrium lies far to the right. B) The equilibrium lies far to the left. C) The reaction is exothermic. D) The reaction is slow. EXAM1 VERSIONA Page6of11

7 UW VERSIONA CHEM152,Sp11 LONGANSWER.60POINTSTOTAL Unlessotherwiseindicated,youmustshowallyourworkandinclude unitsonallvalues(evenintermediatevalues)toearnpartialorfullcredit. Youmayignoresignificantfigures. 9. (30 pts) One mole of an ideal monatomic gas at 3.0 atm and 298 K (V i = 8.15 L) undergoes the following two-step process: 1. Reversible isothermal (ΔT = 0) expansion to a pressure of 1.0 atm (V f = 24.5 L). 2. Isobaric (ΔP = 0) expansion at 1 atm to a volume of 50.0 L (T f = 609 K). Calculate q, w, ΔE, ΔH, and ΔS for each step. Write your results WITH UNITS (J or J/K) in the spaces provided below. 1: q J w J _ ΔE 1 0 ΔH 1 0 ΔS J K -1 2: q kj w J_ ΔE 2 _3.88 kj ΔH 2 _6.46 kj ΔS JK -1 _ EXAM1 VERSIONA Page7of11

8 UW VERSIONA CHEM152,Sp11 Moreroomfor#9,ifneeded. 9)Step1: ; Step2: EXAM1 VERSIONA Page8of11

9 UW VERSIONA CHEM152,Sp (15 pts total) Zinc oxide can be reduced to molten zinc metal by reacting it with carbon: (A) (10 pts) Using the following thermodynamic data, determine ΔG rxn for this reaction at 25 o C. Express your result in kj. ΔH f (kj/mol) S (J/mol.K) ΔG f (kj/mol) ZnO(s) data not provided C(s) data not provided 6 data not provided Zn(l) CO 2 (g) EXAM1 VERSIONA Page9of11

10 UW VERSIONA CHEM152,Sp cont (B) (5 pts) Using your answer to part (A), determine ΔG f for zinc oxide. Express your result in kj/mol. (If you did not obtain an answer to part (A), use ΔG rxn = 100 kj.) EXAM1 VERSIONA Page10of11

11 UW VERSIONA CHEM152,Sp11 Note: Problem 11 is covered after Section So the material covered by this problem will NOT be on the exam. The problem is solved for completeness. 11. (15 pts) At 25 C, K a = for the dissociation of acetic acid: CH 3 COOH(aq) + H 2 O(l) H 3 O + (aq) + CH 3 COO (aq) (A) (5 pts) What is ΔG o for this process at 25 o C? Express your result in kj. (B) (10 pts) Determine ΔG at 25 C for a solution with the following initial concentrations. Express your result in kj. (If you did not obtain an answer to part A, use ΔG o = +10 kj). [CH 3 COOH] o = 0.10 M [H 3 O + ] o = M [CH 3 COO ] o = M EXAM1 VERSIONA Page11of11