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Exam 2 Chem 111, Section 2 (10:10 am) Fall 1998This test is closed book, closed notes, and closed neighbors. A periodic table andother useful information is available at the end of the test. When told to begin, readthrough the entire exam, and decide which questions you can answer quickly. Afteryou have answered those questions, return to the more involved questions andanswer them.--------------------------------------------------------------------------------------------------------------By signing below, I agree to abide by the University rules and regulationsregarding honesty on exams. I understand that I am not to look at others' exams norallow others to view mine. I hereby state that all answers on the answer sheet aremy own.I understand that Professor Martin considers academic honesty to be central tothe goals of the University and that dishonest behavior will dealt with very seriously.Printed Name: _____________________________________________________________Signature: _________________________________________________________________As soon as you have your OpScan (answer) sheet:1) Place your name where indicated.2) Place your student ID number where indicated, starting at column A.3) Place a "2" in column "K" of the special codes section.Fill in the bubbles corresponding to the above.Failure to correctly enter any of the above 3 items willresult in the deduction of 5 points from your exam.Tear this page off and return with your completed answer sheet.You should take the rest of your exam home with you because ⇒As a homework assignment, you may earn up to 10% of the points you missed onthis exam. Details are at the end of this exam.Exam 2 Chem 111, Section 2 (10:10 am) Fall 1998c = 3.00 x 108 m/sec Compound Specific HeatCapacity (J/g K)h = 6.626 x 10–34 J.sec/photon Cu (s) 0.385h = 3.99 x 10–10 J.sec/mol photons C2H5OH(l) 2.46ethanolNo = 6.022 x 1023 "particles" / mol H2O(s) 2.1∆HFusion of ice = 333 J/g H2O(g) 2.01 nm = 10–9 m H2O(l) 4.184Note that this exam is worth a total of 160 pointsYou have version 2 of the exam. Place 2 in column K of your answer sheet.1a. (8 points) Which of the following is a correct, balanced net ionic equation?(a) Mg(OH)2 (s) + HCl (aq) à MgCl2 (aq)+ H2O (aq)(b•) Mg(OH)2 (s) + 2 H+ (aq) à Mg2+ (aq) + 2 H2O (aq)(c) Mg(OH)2 (s) + 2HCl (aq) à MgCl2 (aq) + 2H2O (aq)(d) Mg(OH)2 (s) + H+ (aq) à Mg2+ (aq) + H2O (aq)(e) none of the above is a correctly balanced net ionic equation2b. (8 points) You are preparing an enzyme sample for an experiment. You have anenzyme stock solution that is 0.1 mM and you would like to dilute this in tobuffer to prepare 0.5 mL of a solution with a final enzyme concentration of 0.02mM. What volume of enzyme stock solution should you add?(a) 1.0 mL (b) 2.0 mL (c•) 0.10 mL (d) 0.20 mL (e) 0.05 mLExam 2 Chem 111, Section 2 (10:10 am) Fall 1998∆H°f kJ/mol(For questions 3-9) Last week the Nobel NH3 (g) -46.11prize in Physiology and Medicine wasNO (g) 90.9awarded for pioneering work which recentlydiscovered the role of nitric oxide (NO) in NO2 (g) 33.18intracellular signaling. The rapid reaction of N2O (g) 82.05NO with oxygen ensures that the lifetime of HNO3 (aq) -207.36such signals is short in aerobic cells:2 NO (g) + O2 (g) → 2 NO2 (g)3b. (8 points) How many moles of O2 are required to react with 0.64 moles NO?(a) 0.16 moles (b•) 0.32 moles (c) 0.64 mole (d) 2 moles (e) 1 molesRequire 1 mol O2 per 2 mol NO. (1/2)(0.64) = 0.32 moles4b. (8 points) How many grams NO2 are produced in the complete reaction of 3.0 gNO?(a•) 4.6 g (b) 0.10 g (c) 3.0 g (d) 1.5 g (e) 2.3 g(3.0 g NO)(1/30.01g/mol) = 0.10 mole NO(3.0 g NO)(1 mol NO2 / 1 mol NO) = 0.10 mole NO2(0.10 mole NO2)(46.01 g mol) = 4.6 g NO25. (8 points) The oxidation number of nitrogen in NO2 is(a) 0 (b•) +4 (c) –2 (d) +2 (e) –46. (8 points) In the above reaction, which species is the reducing agent?(a) NO2 (b) O2 (c•) NO(d) there is no reducing agent here7. (8 points) What is ∆H° for this reaction?(a) –57.7 kJ/mol (b) +57.7 kJ/mol (c) –28.9 kJ/mol(d) +28.9 kJ/mol (e•) –115.4 kJ/mol2(33.18 kJ/mol) - 2(90.9 kJ/mol) = –115.

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