Chem 211 - Exam #3 Sample
Sample Exams are designed to give you an idea of the types of questions you can expect. Problems for this exam will likely be similar to the sample problems, and the questions from a previous exam shown below. However, remember that you are responsible for all material that we have discussed in lecture, as well as material from Chem210, as it relates to the current content.
As you can see, most of the problems are from Chapter 20, aromatic compounds. Good luck.
| Chapter | Problem Numbers |
| 20 | 1, 5, 6, 7, 9, 11, 14a,d,e, 15, 18b,c, 23a,b,c, 25,26 |
| 21 | 1, 3, 4, 6a,b,d, 7 |
| 22 | 1, 2, 8, 10a,b, 14 |
Sample questions from previous exams:
1. Now, show the reaction mechanism for reaction of ethylamine (a primary amine) with acetyl chloride.
2. Describe how you would separate a mixture of the three water-insoluble liquids, aniline (b.p. 184oC), n-butylbenzene (b.p. 183oC), and n-pentanoic acid (b.p. 187oC), recovering each compound pure and in essentially quantitative yield.
3. Draw structures for:
4. Give structures and names of the principal organic products expected from reaction (if any) of 1-phenyl-1-propene with:
5. Specify whether the major product or products of each of the following reactions is meta or a mixture of the ortho and para isomers. Draw the major product(s) and name each.
6. For the nitration of phenol, explain why para substitution is favored over meta substitution.
7. Starting with benzene, write chemical equations showing how each of the following compounds could be prepared as the principal product. Include all reagents, including catalysts.
8. Draw the Kekulé resonance structures that contribute to the structures of the aromatic compounds shown.
9. Give reagents for effecting each of the following reactions and write the principal products. If an ortho, para mixture is expected, show both. If the meta isomer is the expected major product, write only that isomer.
10. Give the major product or products of each of the following Friedel-Crafts reactions.
11. For each of the following electrophilic aromatic substitution reactions, list the reactants and the electrophile involved. If reaction occurs with benzene, predict whether the resulting product would lead to m-, p-, or o- substitution for subsequent reactions involving the reaction product. Indicate whether principal product will be meta-, para-, or ortho-
12. Give structures and names of the principal organic products expected for the following reactions:
13. Starting with benzene, show how to produce in succession (a) nitrobenzene, (b) aniline, (c) benzenediazonium chloride, and (d) chlorobenzene.
14. Show how a carbocation is produced when ethylbromide is treated with BF3, a Lewis acid. Then, show products for a Friedel-Crafts alkylation when this carbocation reacts with toluene.
15. When ethylbenzene is reacted with Br2 in the presence of heat and UV light, you produce only 1-bromo-1-phenylethane. Show the structure for this product. Then, draw resonance contributors for the different free radical structures, after removal of the hydrogen on the benzyl carbon. Explain why no 2-bromo-1-phenylethane will be produced?
17. (a) Show how to produce ethylamine starting with ammonia and ethyl bromide. (b) Then explain why you would also produce triethylamine.
18. Show the product for reaction of triethylamine with 2-bromobutane.
19. Explain why amines, alcohols and acids have high boiling points compared to other organic compounds.