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Worksheet 13CH 235-2FNovember 3, 2014

Short Answer:

1. Define nucleophilic substitution. What are the two reactions?

2. For an SN1 reaction, put the halides in increasing order of leaving group ability. Explain why.

3. For an SN1 reaction, put the halides in increasing order of nucleophilicity. Explain why.

4. Draw a general reaction diagram and mechanism for an SN1 reaction.

5. List some solvents for an SN1 reaction. Are they polar aprotic or polar protic?

6. List the following in order of increasing reactivity under SN1 conditions: Tertiary, secondary, primary alkyl halides.

7. What is the stereochemical outcome of an SN1 reaction? Why?

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8. For an SN2 reaction, put the halides in increasing order of leaving group ability. Explain why.

9. For an SN2 reaction, put the halides in increasing order of nucleophilicity. Explain why.

10. Draw a general reaction diagram and mechanism for an SN2 reaction.

11. List some solvents for an SN2 reaction. Are they polar aprotic or polar protic?

12. List the following in order of increasing reactivity under SN2 conditions: Tertiary, secondary, primary alkyl halides.

13. What is the stereochemical outcome of an SN2 reaction? Why?

Multiple Choice:

1. Which of the following is/are true regarding vinyl carbocations?A. They are stable because the cation is on an sp2 carbon.B. They are more stable than a methyl carbocation.C. They are unstable due to the cation being on an sp2 carbon.

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D.

They are unstable due to the cation being on an sp carbon.E. None of the above.

2. Which of the following alkyl halides has the highest boiling point?

3. Which of the following products will be produced in the reaction of 2-methyl-

2-butene with NBS?

A. 3-bromo-2-methyl-1-buteneB. 3-bromo-3-methyl-1-buteneC. 1-bromo-3-methyl-2-buteneD. 1-bromo-2-methyl-2-buteneE. All are possible products.

4. Which of the following statements is/are true regarding Hammond’s Postulate?

I. For an endothermic reaction, the transition state occurs late and resembles the products.

II. For an exothermic reaction, the transition state occurs early and resembles the reactants.

III. It helps explain why radical chlorination is highly selective.

A. I, II, IIIB. I, IIIC. I, IID. III onlyE. None of the above.

5. Which of the following nucleophiles is the best for an SN2 reaction in the solvent DMSO?

A. F-B. Cl-C. Br-

A B C D E

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D. I-E. All are equally good nucleophiles.

6. Put the

following in order of increasing reactivity in an SN1 reaction.

A. I<III<IV<V<IIB. V<II<IV<I<IIIC. III<IV<II<V<ID. I<V<II<IV<IIIE. I<III<V<II<IV

I II III IV V