Exam 4- - Version 116 Exam 4 Holcombe(52460 This print-out should have 28 questions Multiple-choice questions may continue on the next column or page nd

Exam 4- - Version 116 Exam 4 Holcombe(52460 This print-out...

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Version 116 – Exam 4 – Holcombe – (52460) 1 This print-out should have 28 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0 points Consider the data below: [CH 4 ] [O 2 ] initial rate M M M · s 1 Exp 1 0 . 5 1 . 3 2 . 5 × 10 3 Exp 2 0 . 5 2 . 6 1 . 0 × 10 2 Exp 3 1 . 0 1 . 3 5 . 0 × 10 3 Which of the following is a correct rate law for the reaction? 1. k [CH 4 ] 1 [O 2 ] 2. k [CH 4 ][O 2 ] 3. k [CH 4 ] 1 [O 2 ] 2 4. k [CH 4 ][O 2 ] 2 correct 5. k [CH 4 ] Explanation: rate 1 rate 2 = [O 2 ] 1 [O 2 ] 2 2 . 5 × 10 3 1 . 0 × 10 2 = parenleftbigg 1 . 3 2 . 6 parenrightbigg x x = 2 rate 3 rate 1 = [CH 4 ] 3 [CH 4 ] 1 5 . 0 × 10 3 2 . 5 × 10 3 = parenleftbigg 1 . 0 0 . 5 parenrightbigg y y = 1 002 10.0 points Biochemical reactions are most often cat- alyzed by 1. isomers 2. prostaglandins 3. heat energy 4. monomers 5. NSAIDs 6. enzymes correct Explanation: Enzymes are biological catalysts. 003 10.0 points Consider the concentration-time dependence graph for a first-order reaction. [A] 0 Molar Concentration of Reactant A B C Concentration -→ Time -→ At which point on the curve is the reaction fastest? 1. B 2. A correct 3. The rates are the same at all points. 4. A + t 1 / 2 5. C Explanation: Steeper portions of the graph define faster reactions. 004 10.0 points Consider the reaction 2 NOCl(g) 2 NO(g) + Cl 2 (g) with rate constant 0.0480 M 1 · s 1 when con- ducted at 200 C. The initial concentration of
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Version 116 – Exam 4 – Holcombe – (52460) 2 NOCl was 0.521 M. What is the concentrationof NOCl after 0.268 minutes and at 200C? 3.0.289 Mcorrect4.0.372 M5.0.514 M6.0.111 MExplanation:k= 0.0480 M1·s1t= 0.268 min[A]0= 0.521 MThe units onkindicates a second orderreaction:1[A]t-1[A]0=akt 00510.0 pointsConsider the elementary reaction:CaCO3(s)-→CO2(g) + CaO(s)Ifk= 1.03×102M·s1, and there is ini-tially 0 MCO2, what is the [CO2] after 10minutes have passed? 1. 6 . 18 M correct 2. 0 . 10 M 3. 1 . 03 M 4. 0 . 62 M (part 1 of 4) 10.0 pointsConsider the following potential energy dia-gram.efcdabA+BX+YReaction progressPotential energyWhich arrow represents the potential en-ergy of the reactants?
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