The following quiz contains 30 questions valued at 1 point/question unless otherwise noted. Name:

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1 Chemistry 261 Quiz 2 Practice Fall 2017 The following quiz contains 30 questions valued at 1 point/question unless otherwise noted ame: ELECTR DEFICIET CMPUDS AD LEWIS ACID-BASE DEFIITIS 1. Which of the following is not a Lewis acid? a. Al 4 b. AlCl 3 c. (C 3 ) 3 C + d. B 2 6 (diborane) e. BF 3 ELECTR DEFICIET CMPUDS AD LEWIS ACID-BASE REACTIS 2. Which of the following is the product of the reaction between ammonia and borane (B 3 ) 1? a B 2 b B 4 c. 3 + B 3 d. 3 B 3 e. 3 B 3 UCLEPILES, ELECTRPILES, AD LEAVIG GRUPS 3. In the reaction between n-propyl chloride and sodium hydroxide to form n-propanol and sodium chloride, the electrophile is a. a + b. c. Cl d. C bearing Cl e. A 2 o carbocation 1 The interested student may want to contrast borane with diborane

2 UCLEPILES, ELECTRPILES, AD LEAVIG GRUPS 4. Which of the following is the best leaving group? a. R 2 b. R c. R d. R C 3 e. R Br BRØSTED-LWRY ACIDS AD BASES CJUGATE ACID AD BASE DEFIITI 5. Which of the following is the conjugate base of sulfuric acid? a. S 4 b. S 3 c. S 4 d. S 3 e. 2 BRØSTED-LWRY ACIDS AD BASES CJUGATE ACID AD BASE DEFIITI 6. Which of the following are Brønsted bases in the following equilibrium? P P a. P and P 4-3 b. P 4 and - -3 c. P 4 and 2 d. 2 and - -2 e. 2 and P 4 FU WIT pk a s 7. Which of the following compounds has a pk a 25? a. C 3 C 2 C 2 C 2 C 2 b. C 3 CC 2 C CC 3 c. C 3 C 2 C 2 C C d. C 3 C 2 C 2 C 2 C=C 2 e. C 3 C 2 C 2 C 2 2

3 FU WIT pk a s 8. Which of the following compounds would remove a hydrogen of pk a 25 from another compound? a. C 3 C 2 a b. C 3 C 2 2 a c. C 3 C 2 a d. C 3 C 2 a e. All of the above would remove a pk a = 25 proton from another compound FU WIT pk a s 9. From which position(s) would a hydrogen be removed by a? a. 1 b. 1 & 2 c. 1, 5, & 6 d. 3, 4, 7, 8, 9 & 10 e. ydrogens are equally likely to be abstracted from all positions by a FREE EERGY AD CEMICAL EQUILIBRIUM 10. Which of the following acids would have the highest standard free energy of activation ( G o a) a. C 3 C 2 b. CF 3 C 2 c. PhC 2 d. Ph e. All of the above have approximately the same G o a

4 STRUCTURE-ACIDITY RELATISIPS 11. Rank the bold-faced hydrogens in the following compounds from most acidic to least acidic. C 2 Ph Ph I II III IV V a. III > V > IV > II > I b. V > IV > III > II > I c. V > III > IV > II > I d. III > V > II > IV > I e. IV > II > I > V > III STRUCTURE-ACIDITY RELATISIPS 12. Rank the bold-faced hydrogens in the following compounds from most acidic to least acidic. C 3 C 3 Ph C I II III IV V a. I > II > III > IV > V b. V > IV > II > III > I c. V > II > IV > III > I d. II > V > IV > III > I e. V > IV > III > II > I

5 STRUCTURE-ACIDITY RELATISIPS 13. Which of the following carboxylic acids is most acidic? a. C 3 C 2 C 2 C 2 b. CClC 2 C 2 C 2 c. C 3 CClC 2 C 2 d. C 3 C 2 CClC 2 e. There is less than 1 pk a unit difference between any of the acids listed ACID-BASE REACTI PRDUCT PREDICTI CURVED ARRW APPRAC 14. What is/are the products of the following acid-base mechanism? C a. b. C + C + (C 3 ) 2 + (C 3 ) 2 c. C + (C 3 ) 2 d. C + (C 3 ) 2 e. one of the above

6 ACID-BASE REACTI PRDUCT PREDICTI CURVED ARRW APPRAC 15. What is/are the products of the following acid-base mechanism? a. + b. c. + + C 2 =C 2 d. + e. one of the above STRUCTURE AD BDIG I ALKEES 16. Which of the following is a true statement a. The bond results from an end to end overlap of unhybridized p orbitals b. A bond always occurs when sp 2 hybridized atoms bond c. A * molecular orbital is of lower energy than a molecular orbital d. Alkenes do not undergo rotation since a bond is stronger than a bond e. All of the above statements are BS

7 STRUCTURE AD BDIG I ALKEES 17. The geometry of a -bonded system is a. near b. Pyramidal c. Trigonal planer d. Tetrahedral e. Dependent on the number of bonds DUBLE BD STEREISMERS/CIS-TRAS & E,Z MECLATURE 18. Please draw the structure for (Z)-2-butenoic acid DUBLE BD STEREISMERS/CIS-TRAS & E,Z MECLATURE 19. Please name the following compound, adhering to IUPAC conventions, including the E,Z stereoisomer designation ame: USATURATI UMBER R IDEX F YDRGE DEFICIECY 20. What is the unsaturation number for 3-vinylcyclopent-2-en-1-ol? a. 0 b. 1 c. 2 d. 3 e. 4

8 PYSICAL PRPERTIES F ALKEES 21. Which of the following will have the highest boiling point a. 1-pentene b. 1-hexene c. cyclopentene d. cyclohexene e. All of the above boil within 5 o C of one another RELATIVE STABILITIES F ALKEE ISMERS 22. Which of the following has the lowest heat of hydrogenation? a. 1-butene b. cis-2-butene c. trans-2-butene d. 2-methylpropene e. Cyclobutene ADDITI F YDRGE ALIDES/CARBCATI STABILITY/CARBCATI REARRAGEMETS 23. The interaction of an alkene bond with an electrophile can result in the formation of an intermediate species known as a complex. Which of the following cannot form a complex? a. + b. 3 c. Ag + d. g +2 e. BF 3

9 ADDITI F YDRGE ALIDES/CARBCATI STABILITY/CARBCATI REARRAGEMETS 24. Which of the following carbocations would not undergo rearrangement? I II III IV V a. I & IV b. I, III, IV c. II & V d. II & IV e. III only ADDITI F YDRGE ALIDES/CARBCATI STABILITY/CARBCATI REARRAGEMETS 25. When either cis- or trans-2-butene is treated with Cl in ethanol, the product mixture that results includes a. C 3 C 2 C 2 Cl b. C 3 C 2 C 2 C 2 C 3 c. C 3 C 2 C(C 3 )C 2 C 3 d. (C 3 ) 3 CCl e. (C 3 ) 2 CC 2 C 2 C 3 ADDITI F YDRGE ALIDES/CARBCATI STABILITY/CARBCATI REARRAGEMETS 26. Treating 1-methylcyclohexene with 3 + would primarily yield which of the following? I II III a. I & V b. II c. III & V d. IV e. I, III, & V IV V

10 REACTI RATE CSIDERATIS 27. Increasing the temperature of a chemical reaction [usually] increases the rate of reaction considerably (recall the rule of thumb that every 10 o C increase doubles the rate of reaction). The most important reason for this is that increasing the temperature a. Increases the collision frequency b. Decreases the probability factor c. Increases the fraction of collisions with energy > E a d. Decreases the energy of activation e. Makes the reaction more exothermic REACTI RATE CSIDERATIS 28. Which of the following is in effect a statement of ammond s postulate? a. Transitions states in unimolecular decompositions involving carbocations resemble the structure of the carbocation b. The energy of activation (E a ) is primarily a reflection of bond strength c. The more stable the conjugate base, the lower the pk a value d. eat and limiting water favors elimination to alkenes over hydration to alcohols e. More than one of the above CATALYSIS/CATALYTIC YDRGEATI F ALKEES 29. ow many moles of diatomic hydrogen will react with 3-vinylcyclo-2-penten-1-ol? a. 0 b. 1 c. 2 d. 3 e. 4 Bonus (1 EC): Was your answer the same as for question 20? Briefly explain

11 CATALYSIS/CATALYTIC YDRGEATI F ALKEES 30. Which of the following will convert styrene (vinyl benzene) to ethyl benzene a. Conc. 2 S 4 / b. 2 /Pd/C c. 2 /i d. More than 1 of the above e. All of the above