3) A compound that is composed of only carbon and hydrogen is known as a(n): A) homolog B) isomer C) carbohydrate D) hydrocarbon Answer: D

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1 Chapter 4 Introduction to Organic Compounds 4.1 Multiple-Choice 1) The compound CH3(CH2)5CH3 is called: hexane pentane heptane octane 2) The compound CH3(CH2)4CH3 is called: hexane pentane heptane butane 3) A compound that is composed of only carbon and hydrogen is known as a(n): homolog isomer carbohydrate hydrocarbon Answer: D 4) How many carbon atoms are in a butane molecule? ) Which of these hydrocarbons could not be a cycloalkane? C3H6 C4H8 C5H10 C6H14 6) Which of these formulas corresponds to that of a straight-chain alkane? C5H10 C6H12 C5H12 C7H14 7) Which of the following structures is cyclopentane? 1

2 8) Which of the following is the correct condensed structural formula for octane? CH3CH2CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH2CH2CH2CH3 9) What is the correct skeletal structure for hexane? 10) What is the correct condensed structural formula for this skeletal structure? CH3(CH2)5CH3 CH3(CH2)6CH3 CH3(CH2)7CH3 CH3(CH2)8CH3 Answer: C 11) Which of these molecules is aromatic? 2

3 12) Which of these functional groups is an alcohol? R-S-H R-O-H R-S-S-H R-S-S-R' 13) Which of these functional groups is a phenol? 14) Which of these molecules is a tertiary amine? RNH2 R2NH R3N R2NH+ 3

4 15) Which of these molecules is a ketone? 16) Which of these molecules is an ester? 4

5 17) Which of the following is a secondary alcohol? 18) Which of the following is a primary alcohol? 19) Which of the following is a tertiary alcohol? 5

6 20) Which of these molecules is saturated 21) Which of these molecules is an alkyne? 22) Which of the following is the structure for stearic acid? CH3(CH2)14COOH CH3(CH2)16COOH CH3(CH2)12COOH CH3(CH2)10COOH 6

7 23) How many carbon atoms are in a molecule of palmitic acid? ) A molecule that has both polar and nonpolar parts is said to be: an isomer amphipathic an enantiomer hydrophobic 25) What functional groups are present in the following structure? CH3 C C CH2OH Alcohol and an alkene A ketone and an alkyne An aldehyde and a ketone An alcohol and an alkyne 26) All members of the alkene series of hydrocarbons have the general formula: CnH2n CnHn CnH2n+2 CnH2n-2 27) The name of the following alkyl group is: Isobutyl Isopropyl Propyl Butyl 28) What is the IUPAC name for the following structure? Ethyl cyclohexane 1-chloro-2-ethyl cyclohexane Chloro-ethyl cyclohexane 2-chloro-2-ethyl cyclohexane 7

8 29) Which of the following structures is correct for 1,2-dibromo-2-methyl butane? 30) What is the correct name for the following compound? 4-chloropentane 4-chlorohexane 2-chloropentane 2-chloropropane 31) Which of the following is the correct structure for 2,3-dimethyl pentane? 8

9 32) Which of the following is the correct structure for 1-ethylcyclopentane? 33) What is the correct name for the following compound? 4-ethyl-2-methylhexane 3,5-dimethylheptane 2-ethyl-4-methylhexane 2,4-dimethylhexane 34) The name of the following alkyl group is: CH3CH2- Methyl Isopropyl Propyl Ethyl 35) What is the relationship between the following molecules? They are identical. They are isomers of each other. 9

10 They are different molecules which are not isomers. 36) When two compounds are made up of the same number and kind of atoms, but differ in their molecular structure they are known as: isotopes homologs isomers hydrocarbons 37) How many isomers are there of hexane, C6H14? ) Which of the following is a structural isomer of 2-methylbutane? n-propane 2-methylpropane n-butane n-pentane 39) Among the following compounds which are isomers? I and II I and III I and IV II and III 40) Which of these molecules is not an isomer of the others? 41) Which of the following alkenes shows cis-trans isomerism? 1,1-difluorobutene 10

11 1-pentene 2-methyl-2-octene 3-octene 42) What is the IUPAC name for the following structure? 1,2-dimethyl cyclohexane trans-1,2-dimethyl cyclohexane cis-1,2-dimethyl cyclohexane 5,6-dimethyl cyclohexane 43) Which of the following is cis-2,3-dichloro-2-butene? 44) Which of the following molecules contains a chiral carbon? 11

12 45) What is the correct name for the following structure? Dichlorocyclopentane Cis-dichlorocyclopentane 1,2-dichlorocyclopentane Trans-dichlorocyclopentane 46) Which of the following compounds is the enantiomer of: 12

13 47) How many chiral carbon atoms are in this structure? ) How many chiral carbon atoms are in this molecule? ) How many chiral carbon atoms are in this molecule?

14 4.2 Short Answer 1) Draw the skeletal structure for octane. Answer: 2) Draw the skeletal structure for cyclobutane. Answer: Diff: 1 Section: 4-2 3) Write the condensed structural formula for this alkane: 4) Draw the general structure for a carboxylic acid. 5) Draw the general structure for an aldehyde. 6) Draw the general structure for a ketone. 7) Draw the general structure for an ester. 8) Identify the "1" and "12" carbon atoms in lauric acid 9) Identify all the functional groups in the following molecules: 14

15 10) Name the following compounds: Answer: 1-bromo-3-methyl cyclohexane; 1-chloro-2-ethyl-1-methyl cyclopentane; 1-methyl-1-propyl cyclobutane 11) Either write the name or draw the following compounds: 1,3-difluoro-2-methyl pentane 4-ethyl-3,3-dimethylnonane E) 3,4-dichloro-5-methylheptane 12) Draw the condensed formulas for the following compounds: 2,4-dimethyl pentane 3-isopropyl octane 2-ethyl-1,3-dimethylcyclohexane 4-ethyl-2-methyl hexane E) 2-methyl-4-propyl heptane 13) A tetrahedral carbon atom will be chiral if it has four groups attached to it. 14) Mark the chiral carbons in the following molecules: 15