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CHEM 203
Exam 1
_____________KEY______________
Name
Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.
_D__
1. Which of the following elements is a large percentage of both the earth's crust and of organic
compounds?
a. carbon
b. nitrogen
c. oxygen
d. none of these
_C__
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
b. 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
_C__
3. Which of the following is the expected H-C-H bond angle in formaldehyde, CH2O?
a. 90o
b. 109.5o
c. 120o
d. 180o
_D__
4. Which of the following is the expected H-C-C bond angle in acetylene, C2H2?
a. 90o
b. 109.5o
c. 120o
d. 180o
_C__
5. Which of the following is the expected H-C-H bond angle in ethylene, C2H4?
a. 90o
b. 109.5o
c. 120o
d. 180o
6. The chemical formula of urea is (NH2)2CO. How many valence electrons are associated with a
molecule of urea?
a. 4
b. 8
c. 16
d. 24
_D__
_A__
7. Which of the following functional groups contains a nitrogen atom?
a. amino
b. carbonyl
c. carboxyl
d. hydroxyl
_B__
8. The hydroxyl group is the functional group of which of the following types of compounds?
a. acids
b. alcohols
c. aldehydes
d. amines
_D__
9. The functional group of aldehydes is often written as –CHO. Which of the following is true?
a. the carbon atom forms two bonds
b. the hydrogen atom forms two bonds
c. the oxygen atom forms one bond
d. none of the above is true
_C__ 10. What is the minimum number of carbon atoms present in a tertiary alcohol?
a. 2
b. 3
c. 4
d. 5
_B__ 11. What is the minimum number of carbon atoms present in a tertiary amine?
a. 2
b. 3
c. 4
d. 5
_C__ 12. Which of the following classes of organic compounds contains atoms other than carbon and
hydrogen?
a. alkanes
b. alkenes
c. amines
d. arenes
_B__ 13. Which of the following is(are) characteristic of a saturated hydrocarbon?
a. it contains as much solute as it can
b. it contains the maximum possible number of hydrogen atoms for a given number of carbon
atoms
c. both (a) and (b)
d. neither (a) nor (b)
_C__ 14. Which of the following is the methylene unit?
a. CH4
b. –CH3
c. –CH2–
d.
_D__ 15. Which of the following is the generic formula for straight chain alkanes?
a. CnH2n-4
b. CnH2n-2
c. CnH2n
d. CnH2n+2
_D__ 16. Which of the following is the condensed structural formula of butane?
a. CH3(CH2)4CH3
b. CH3(CH2)5CH3
c. CH3(CH2)6CH3
d. none of these
_D__ 17. What is the formula of the lightest hydrocarbon which exists as constitutional isomers?
a. CH4
b. C2H6
c. C3H8
d. none of these
_B__ 18. Which of the following is(are) constitutional isomer(s) of pentane, CH3(CH2)3CH3?
a.
b.
c. both (a) and (b)
d. neither (a) nor (b)
_B__ 19. How many constitutional isomers are there with the formula C5H12?
a. 2
b. 3
c. 4
d. 5
_C__ 20. How many constitutional isomers are there with the formula C6H14?
a. 3
b. 4
c. 5
d. 6
_B__ 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
b. 2
c. 3
d. 4
_C__ 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
b. we do not consider the size of the substituents when determining the order of naming them
c. both (a) and (b) are true
d. neither (a) nor (b) is true
_C__ 23. What is the IUPAC name of
a.
b.
c.
d.
propylbutane
2-ethylpentane
3-methylhexane
4-methylhexane
_C__ 24. Which of the following formulas describes the composition of cycloalkanes?
a. CnH2n-4
b. CnH2n-2
c. CnH2n
d. CnH2n+2
_C__ 25. Which of the following molecules exists as cis-trans isomers?
a. 1,2-dimethylcyclohexane
b. 1,3-dimethylcyclohexane
c. both (a) and (b)
d. neither (a) nor (b)
_A__ 26. What is the name of
a.
b.
c.
d.
cis-1-ethyl-4-methylcyclohexane
cis-1-methyl-4-ethylcyclohexane
trans-1-ethyl-4-methylcyclohexane
trans-1-methyl-4-ethylcyclohexane
_B__ 27. Which of the following endings is used for compounds which contains a carbon-carbon double
bond?
a. -ane
b. -ene
c. -yne
d. -yl
_D__ 28. Which of the following compounds with formula C5H10 has cis-trans isomers?
a. 1-pentene
b. 2-methyl-2-butene
c. both (a) and (b)
d. neither (a) nor (b)
_C__ 29. Which of the following is the generic formula of trienes?
a. CnH2n
b. CnH2n-2
c. CnH2n-4
d. none of these
_B__ 30. Which of the following reactions is regioselective?
a. halogenation
b. hydration
c. both (a) and (b)
d. neither (a) nor (b)
_B__ 31. What is the product of the addition of HBr to
a.
b.
c.
d.
_B__ 32. Which of the following is a secondary carbocation?
a.
b.
c. both (a) and (b)
d. neither (a) nor (b)
_A__ 33. Which combination of reactants will react to produce only 2-bromopentane?
a. HBr and 1-pentene
b. HBr and 2-pentene
c. Br2 and 1-pentene
d. Br2 and 2-pentene
_C__ 34. Which of the following is true of polyethylene?
a. its physical properties depend on the method of preparation
b. the polymer contains no carbon-carbon double bonds
c. both (a) and (b)
d. neither (a) nor (b)
_C__ 35. Which of the following compounds does not have a special name but is named as a derivative of
benzene?
a.
b.
c.
d. none, they all have special names
_A__ 36. Which of the following catalysts is required for the synthesis of bromobenzene?
a. FeCl3
b. H2SO4
c. nickel
d. none, no catalyst is required
_A__ 37. Which of the following compounds is commonly called p-chlorotoluene?
a. 1-chloro-4-methylbenzene
b. 1-methyl-4-chlorobenzene
c. 1-chloro-3-methylbenzene
d. 1-chloro-2-methylbenzene
_D__ 38. Which of the following compounds is aniline?
a.
b.
c.
d.
39. In the space provided below, draw all possible structures of C4H8. 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.
1-butene
trans-2-butene
cis-2-butene
2-methylpropene
cyclobutane
methylcyclopropane
40. Write the major product for the following reaction. (3 points)
CH3-CH2-CH2-CH=CH2 + HBr → CH3-CH2-CH2-CHBr-CH3