CHEM 203 Exam 1 Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Which of the following elements is a large percentage of both the earth's crust and of organic compounds? a. carbon nitrogen c. oxygen d. none of these 2. Which of the following is characteristic of an oxygen atom in organic compounds? a. it normally forms four covalent bonds and has no unshared electron pairs it normally forms three covalent bonds and has one unshared electron pair c. it normally forms two covalent bonds and has two unshared electron pairs d. it normally forms one covalent bond and has three unshared electron pairs 3. Which of the following is the expected H-C-H bond angle in formaldehyde, CH 2 O? a. 90 o 109.5 o c. 120 o d. 180 o 4. Which of the following is the expected H-C-C bond angle in acetylene, C 2 H 2? a. 90 o 109.5 o c. 120 o d. 180 o 5. Which of the following is the expected H-C-H bond angle in ethylene, C 2 H 4? a. 90 o 109.5 o c. 120 o d. 180 o 6. The chemical formula of urea is (NH 2 ) 2 CO. How many valence electrons are associated with a molecule of urea? a. 4 8 c. 16 d. 24 7. Which of the following functional groups contains a nitrogen atom? a. amino carbonyl c. carboxyl d. hydroxyl
8. The hydroxyl group is the functional group of which of the following types of compounds? a. acids alcohols c. aldehydes d. amines 9. The functional group of aldehydes is often written as CHO. Which of the following is true? a. the carbon atom forms two bonds the hydrogen atom forms two bonds c. the oxygen atom forms one bond d. none of the above is true 10. What is the minimum number of carbon atoms present in a tertiary alcohol? a. 2 3 c. 4 d. 5 11. What is the minimum number of carbon atoms present in a tertiary amine? a. 2 3 c. 4 d. 5 12. Which of the following classes of organic compounds contains atoms other than carbon and hydrogen? a. alkanes alkenes c. amines d. arenes 13. Which of the following is(are) characteristic of a saturated hydrocarbon? a. it contains as much solute as it can it contains the maximum possible number of hydrogen atoms for a given number of carbon atoms 14. Which of the following is the methylene unit? a. CH 4 CH 3 c. CH 2 d. 15. Which of the following is the generic formula for straight chain alkanes? a. C n H 2n-4 C n H 2n-2 c. C n H 2n d. C n H 2n+2
16. Which of the following is the condensed structural formula of butane? a. CH 3 (CH 2 ) 4 CH 3 CH 3 (CH 2 ) 5 CH 3 c. CH 3 (CH 2 ) 6 CH 3 d. none of these 17. What is the formula of the lightest hydrocarbon which exists as constitutional isomers? a. CH 4 C 2 H 6 c. C 3 H 8 d. none of these 18. Which of the following is(are) constitutional isomer(s) of pentane, CH 3 (CH 2 ) 3 CH 3? a. 19. How many constitutional isomers are there with the formula C 5 H 12? a. 2 3 c. 4 d. 5 20. How many constitutional isomers are there with the formula C 6 H 14? a. 3 4 c. 5 d. 6 21. In a branched alkyl group the prefix sec- is used when the carbon with the available bonding position is bonded to how many other carbon atoms? a. 1 2 c. 3 d. 4 22. When naming compounds in which there are several different substituents which of the following is true? a. we do not include prefixes when considering the order of naming substituents we do not consider the size of the substituents when determining the order of naming them are true is true 23. What is the IUPAC name of
a. propylbutane 2-ethylpentane c. 3-methylhexane d. 4-methylhexane 24. Which of the following formulas describes the composition of cycloalkanes? a. C n H 2n-4 C n H 2n-2 c. C n H 2n d. C n H 2n+2 25. Which of the following molecules exists as cis-trans isomers? a. 1,2-dimethylcyclohexane 1,3-dimethylcyclohexane 26. What is the name of a. cis-1-ethyl-4-methylcyclohexane cis-1-methyl-4-ethylcyclohexane c. trans-1-ethyl-4-methylcyclohexane d. trans-1-methyl-4-ethylcyclohexane 27. Which of the following endings is used for compounds which contains a carbon-carbon double bond? a. -ane -ene c. -yne d. -yl 28. Which of the following compounds with formula C 5 H 10 has cis-trans isomers? a. 1-pentene 2-methyl-2-butene 29. Which of the following is the generic formula of trienes?
a. C n H 2n C n H 2n-2 c. C n H 2n-4 d. none of these 30. Which of the following reactions is regioselective? a. halogenation hydration 31. What is the product of the addition of HBr to a. c. d. 32. Which of the following is a secondary carbocation? a. 33. Which combination of reactants will react to produce only 2-bromopentane? a. HBr and 1-pentene HBr and 2-pentene c. Br 2 and 1-pentene d. Br 2 and 2-pentene 34. Which of the following is true of polyethylene?
a. its physical properties depend on the method of preparation the polymer contains no carbon-carbon double bonds 35. Which of the following compounds does not have a special name but is named as a derivative of benzene? a. c. d. none, they all have special names 36. Which of the following catalysts is required for the synthesis of bromobenzene? a. FeCl 3 H 2 SO 4 c. nickel d. none, no catalyst is required 37. Which of the following compounds is commonly called p-chlorotoluene? a. 1-chloro-4-methylbenzene 1-methyl-4-chlorobenzene c. 1-chloro-3-methylbenzene d. 1-chloro-2-methylbenzene 38. Which of the following compounds is aniline?
a. c. d.
39. In the space provided below, draw all possible structures of C 4 H 8. After drawing your structures, provide the proper IUPAC name of each structure. (2 points per structure) Note: They have to be constitutional or stereo isomers to count. Additionally, multiple representations of the same structure as well as the presence of incorrect structures (improper carbon and/or hydrogen count) may lead to point deductions. 40. Write the major product for the following reaction. (3 points) CH 3 -CH 2 -CH 2 -CH=CH 2 + HBr