General, Organic, and Biological Chemistry, 3e (Timberlake) Chapter 11 Introduction to Organic Chemistry: Alkanes 11.1 Multiple-Choice Questions 1) Compounds that have the same molecular formula but different arrangements of atoms are called A) isomers. B) isotopes. C) indicators. D) isozymes. E) isometrics. Answer: A 2) Which of the following is true of nonane, C9H20, which has a density of 0.79 g/mL, melts at 51 °C, and boils at 157 °C? A) Nonane is soluble in water. B) Nonane is a gas at room temperature. C) Nonane is a solid at room temperature. D) Nonane does not undergo combustion. E) Nonane floats on the surface of water. Answer: E 3) A formula that shows the arrangement of all bonds in a molecule is called a(n) A) molecular formula. B) complete structural formula. C) condensed structural formula. D) condensed molecular formula. E) isomeric formula. Answer: B 4) In the three-dimensional structure of methane, CH4, the hydrogen atoms attached to a carbon atom are aligned A) in a straight line. B) at the corners of a square. C) at the corners of a tetrahedron. D) at the corners of a rectangle. E) at the corners of a cube. Answer: C 5) Which one of the following is NOT an organic substance? A) an antibiotic B) nylon C) coal D) silk E) salt, sodium chloride Answer: E 1 6) A hydrocarbon contains only the elements A) hydrogen and oxygen. B) carbon and oxygen. C) carbon and hydrogen. D) carbon, hydrogen, and oxygen. E) carbon, hydrogen, and nitrogen. Answer: C 7) The functional group contained in the compound CH3CH2OH is a(n) A) aldehyde. B) alkene. C) alcohol. D) ketone. E) ether. Answer: C 8) What type of compound is CH3CH2CH2Cl? A) alkane B) branched alkane C) cycloalkane D) haloalkane E) isomer Answer: D 9) What type of compound is CH3-CH2-CH3? A) alkane B) branched alkane C) cycloalkane D) haloalkane E) isomer Answer: A 10) What is the name of this compound? Cl | CH3-CH – CH2- CH2 - Cl? A) 1,1-dichlorobutane B) 1,2,-dichlorobutane C) 1,3-dichlorobutane D) 1,4-dichlorobutane E) dichlorobutane Answer: C 2 11) The special feature that determines the family name and chemical reactivity of the organic compound it is found in is called a(n) A) functional group. B) organic compound. C) identifying group. D) ionic bond. E) covalent bond. Answer: A 12) VSEPR theory predicts that simple carbon compounds will form bonds that are A) as far apart as possible. B) as close together as possible. C) arranged in a straight line. D) pointed to the corners of a cube. E) pointed to the corners of a triangle. Answer: A 13) A molecule containing a carbon atom bonded to four chlorine atoms has the shape of a A) triangle. B) rhombus. C) square. D) cube. E) tetrahedron. Answer: E 14) The bond angles of tetravalent carbon are all approximately A) 90° B) 109.5° C) 60° D) 99.5° E) 45° Answer: B 15) As carbon bonds with atoms of increasingly higher electronegativities, the polarity of the bond A) decreases. B) increases. C) stays the same. D) reverses. E) becomes inverted. Answer: B 16) Carbon tetrachloride has a polar C-Cl bond. What is the overall polarity of the carbon tetrachloride molecule? A) weakly polar B) strongly polar C) reversed polarity D) nonpolar E) inverse polarity Answer: D 3 17) Which of the following is NOT typical of most organic compounds? A) high melting point B) poor solubility in water C) low boiling point D) covalent bonding E) high flammability Answer: A 18) A functional group is a certain group of atoms that A) increases water solubility. B) reacts in a predictable way whenever present. C) changes the color of the molecule whenever present. D) always contains oxygen or nitrogen. E) never contains a halogen. Answer: B 19) An alkene is always a carbon compound that contains a __________ bond. A) single B) double C) triple D) aromatic E) hydrogen Answer: B 20) An alkyne is always a carbon compound that contains a __________ bond. A) single B) double C) triple D) aromatic E) hydrogen Answer: C 21) The functional group contained in the compound CH3CHO is a(n) A) aldehyde. B) alkene. C) alcohol. D) ketone. E) ether. Answer: A 22) The functional group contained in the compound A) aldehyde. B) alkene. C) alcohol. D) ketone. E) ether. Answer: A 4 is a(n) 23) The functional group contained in the compound (CH3CH3)2O is a(n) A) aldehyde. B) alkene. C) alcohol. D) ketone. E) ether. Answer: E 24) The functional group contained in the compound CH3-CH2-O-CH2-CH3 is a(n) A) aldehyde. B) alkene. C) alcohol. D) ketone. E) ether. Answer: E 25) The functional group contained in the compound CH3CH2CH=CHCH3 is a(n) A) aldehyde. B) alkene. C) alcohol. D) ketone. E) ether. Answer: B 26) The functional group contained in the compound CH3CH2COOCH3 is a(n) A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: D 27) The functional group contained in the compound CH3CH2SH is a(n) A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: A 28) The functional group contained in the compound CH3CH2COOH is a(n) A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: B 5 29) The functional group contained in the compound CH3CH2CONH2 is a(n) A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: E 30) The functional group(s) contained in the compound shown below is (are) A) an amine. B) an aromatic. C) an amide. D) an amine and an aromatic. E) an amide and an aromatic. Answer: D 31) The functional group contained in the compound A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: E is a(n) 32) The functional group contained in the compound A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: D is a(n) 33) The functional group contained in the compound A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: B 6 is a(n) 34) The functional group contained in the compound CH3CH2NH2 is a(n) A) thiol. B) carboxylic acid. C) amine. D) ester. E) amide. Answer: C 35) Isomers are molecules that share the same formula and have A) a different shape to the molecule. B) the same arrangement of atoms within the molecule. C) a different arrangement of atoms within the molecule. D) identical boiling points. E) the same shape in each molecule. Answer: C 36) Organic chemistry is the study of the chemistry of compounds of A) oxygen. B) hydrogen. C) living things. D) polymers. E) carbon. Answer: E 37) How does a molecule of a vitamin synthesized in the laboratory behave when compared to the behavior of the same vitamin isolated from a natural source (e.g., vitamin C synthesized, compared to vitamin C from rose hips)? A) identical in every way B) usually identical C) Some effects are the same. D) Few effects are the same. E) The natural vitamin is better. Answer: A 38) How many valence electrons does carbon have? A) one B) two C) three D) four E) five Answer: D 39) Carbon atoms always have how many covalent bonds? A) one B) two C) three D) four E) five Answer: D 7 40) Hydrocarbons are the primary constituents of A) drugs. B) food flavors. C) fossil fuels. D) fruit juices. E) disinfectants. Answer: C 41) Identify the functional group in the compound CH3CH2NH2 . A) amide B) quaternary amine C) tertiary amine D) secondary amine E) primary amine Answer: E 42) Identify the functional group in the compound CH3CH2CHO. A) amide B) ketone C) ester D) secondary amine E) aldehyde Answer: E 43) Identify the functional group in the compound CH3CH2NHCH3. A) amide B) quaternary amine C) tertiary amine D) secondary amine E) primary amine Answer: D 44) Identify the functional group in the compound CH3CH2N(CH3)2 . A) amide B) alcohol C) amine D) ether E) ketone Answer: C 45) An organic compound composed of carbon and hydrogen connected only by single bonds is an A) alkane. B) alkene. C) alkyne. D) aromatic compound. E) alcohol. Answer: A 8 46) One reason for the very large number of organic compounds (compared to the total number of inorganic compounds) is A) functional groups. B) constitutional isomerism. C) hydrogen bonding. D) the occurrence of organic compounds in living things. E) the electronegativity of carbon. Answer: B 47) In a molecule with a symmetrical arrangement of polar bonds, the overall molecule is A) highly polar. B) somewhat polar. C) nonpolar. D) reverse polar. E) strongly reverse polar. Answer: C 48) Organic compounds that are poorly soluble in water behave that way because they are A) highly polar. B) moderately polar. C) covalently bonded. D) generally nonpolar. E) ionically bonded. Answer: D 49) Generally, a solution of an organic compound in water will be electrically A) highly conductive. B) highly ionized. C) nonconductive. D) insulated. E) charged. Answer: C 50) Which of the following is NOT a representation for a carboxylic acid functional group? A) CHO B) COOH C) CO2H D) C(=O)OH E) O - C - OH Answer: A 51) In an amine functional group, the central atom is A) carbon. B) hydrogen. C) oxygen. D) nitrogen. E) sulfur. Answer: D 9 52) A thiol is a functional group containing A) carbon. B) chlorine. C) oxygen. D) nitrogen. E) sulfur. Answer: E 53) In the equation for the combustion of pentane, the coefficient of carbon dioxide is A) one B) two. C) three. D) four. E) five. Answer: E 54) Which of these formulas is the expanded structural formula for an alkane with three carbon atoms? A) C3H6 B) C3H83 C) CH3- CH2- CH3 D) C - C - C E) Answer: E 55) What is the condensed structural formula for an alkane with four carbon atoms? A) CH3-CH=CH- CH3 B) CH3-CH2-CH2- CH3 C) C4H10 D) C - C - C - C E) Answer: B 10 56) What is the name of the continuous chain alkane with six carbon atoms? A) butane B) pentane C) hexane D) heptane E) octane Answer: C 57) What is the name of this compound? CH3-CH2-CH2-CH2-CH2-CH2-CH3 A) hexane B) heptane C) octane D) butane E) pentane Answer: B 58) What is the name of this compound? CH3-CH2-CH2-CH2-CH3 A) pentane B) hexane C) heptane D) octane E) methylbutane Answer: A 59) What is the name of CH3-CH2-CH2-CH3? A) ethane B) propane C) butane D) pentane E) hexane Answer: C 60) The IUPAC name for CH3 -Cl is A) methyl chloride B) chloromethane. C) methanechlorine. D) chloroethane. E) methane chloride. Answer: B 11 61) The major product formed when bromine reacts with propane is A) 1-bromopropane. B) 2-bromopropane. C) 3-bromopropane. D) propyl bromide. E) bromopropane. Answer: B 62) What is the IUPAC name for CH3 ∣ CH3-CH2-CH2-CH- CH2-CH3 A) 4-methylhexane. B) 3-methylhexane. C) heptane. D) methylhexane. E) 2-methylhexane. Answer: B 63) What is the IUPAC name for CH3 │ CH2-CH2-CH2-CH3 A) 1-methylbutane. B) 4-methylbutane. C) pentane. D) butane. E) hexane. Answer: C 64) What is the IUPAC name for Cl-CH2 -CH2 - CH2-Cl A) 1,3-dichloropropane. B) 1,1-dichloropropane. C) dichloropropane. D) 1,3-dichlorobutane. E) propane dichloride. Answer: A 65) What is the name of A) pentane B) methylpentane C) 2-methylpentane D) 4-methylpentane E) hexane Answer: C ? 12 66) What is the name of ? | CH3 A) hexane B) dimethylbutane C) 3,3-dimethylbutane D) 2,2-dimethylbutane E) 2-dimethylbutane Answer: D 67) What is the IUPAC name of A) 1,2-dichloro-3-methylpentane B) 1,2-dichloro-3-methylcyclopentane C) 1-methyl-2,3-dichlorocyclopentane D) 3-methyl-1,2-dichlorocyclopentane E) 1,2-dichloro-3-methylcyclobutane Answer: B ? 68) Which of the following pairs of compounds are isomers? A) B) C) D) E) Answer: C 13 69) Which of the following pairs of formulas represent isomers? A) B) C) D) E) Answer: E 70) A cycloalkane A) has two fewer carbon atoms than the corresponding alkane. B) has two fewer hydrogen atoms than the corresponding alkane. C) contains - CH3 groups joined by single bonds. D) always contains a three carbon ring. E) has no hydrogen atoms. Answer: B 71) The simplest cycloalkane has A) one carbon atom. B) two carbon atoms. C) three carbon atoms. D) four carbon atoms E) five carbon atoms. Answer: C 14 72) What is the IUPAC name of this alkane? A) 4-ethyl-2,2-dimethylpentane B) 2-ethyl-4,4-dimethylpentane C) 2,2,4-trimethylhexane D) 2-ethyl-2,2-dimethylpentane E) 3,5,5-trimethylhexane Answer: C 73) Which of the following compounds could have the molecular formula C7H16? A) hexane B) pentane C) 2-methylheptane D) 2,3-dimethylpentane E) 3-ethylhexane Answer: D 74) The reaction of butane with oxygen is called A) substitution. B) addition. C) neutralization. D) combustion. E) titration. Answer: D 75) What is(are) the product(s) of the complete combustion of any hydrocarbon? A) CO only B) CO2 only C) CO + H2O D) CO2 + H2O E) H2O only Answer: D 76) The balanced equation for the complete combustion of C5H12 will give which of these product(s)? A) CO2 only B) C5H12O5 only C) 5 CO2 + 5H2O D) 5 CO2 + 6H2O E) 10CO + 12H2O Answer: D 15 77) What is the name of the alkyl group CH3- CH2- CH2- ? A) propane B) methyl C) ethane D) ethyl E) propyl Answer: E 78) What is the IUPAC name for this alkane? A) 2-ethyl-3-methylpentane B) 4-ethyl-3-methylpentane C) 3, 4-dimethylhexane D) 2, 3-diethylbutane E) octane Answer: C 79) The reaction for the combustion of heptane is C7H16 + 11 O2 → 7 CO2 + 8H2O. How many liters of CO2 at STP are produced from the complete combustion of 2.00 moles of heptane? A) 44.8 L B) 22.4 L C) 157 L D) 246 L E) 314 L Answer: E 80) What is the name for a one-carbon alkyl substituent? A) methyl B) ethyl C) propyl D) butyl E) pentyl Answer: A 81) What is the name for a two-carbon alkyl group? A) methyl B) ethyl C) propyl D) butyl E) pentyl Answer: B 82) What is the name for a three-carbon saturated alkyl group? 16 A) methyl B) ethyl C) propyl D) butyl E) pentyl Answer: C 83) What is the name for this three-carbon alkyl group? CH3 - CH - CH 3 | A) n-propyl B) iso-propyl C) butyl D) iso-butyl E) ethyl Answer: B 84) What is the name for a four-carbon continuous-chain alkane? A) methane B) ethane C) propane D) butane E) pentane Answer: D 85) What is the name for a five-carbon continuous-chain alkane? A) methane B) ethane C) propane D) butane E) pentane Answer: E 86) What is the mame for a six-carbon continuous-chain alkane? A) hexane B) heptane C) octane D) nonane E) decane Answer: A 87) What is the name for a seven-carbon continuous-chain alkane? A) hexane B) heptane C) octane D) nonane E) decane Answer: B 88) What is the name for an eight-carbon continuous-chain alkane? A) hexane 17 B) heptane C) octane D) nonane E) decane Answer: C 89) What is the name for a nine-carbon continuous-chain alkane? A) hexane B) heptane C) octane D) nonane E) decane Answer: D 90) What is the name for a ten-carbon continuous-chain alkane? A) hexane B) heptane C) octane D) nonane E) decane Answer: E 91) In a condensed structural formula, each carbon atom is A) shown with all individual atoms and bonds drawn. B) shown with only the other carbon atoms. C) grouped with its bonded hydrogen atoms. D) not explicitly shown. E) written in lowercase letters. Answer: C 92) According to the IUPAC convention for chemical naming, which part of a hydrocarbon is selected as the main chain for a hydrocarbon chain? A) the most highly branched chain B) the shortest chain C) the longest chain drawn in a straight line D) the longest continuous chain, regardless of bends E) the chain with the most substituted carbons in it Answer: D 93) According to the IUPAC convention, alkyl group names should be located _____ of the name of the main chain. A) in front B) at the end C) in the middle Answer: A 18 94) According to the IUPAC convention, alkyl substituents on a hydrocarbon chain should be listed in which order? A) alphabetical including prefixes B) alphabetical without considering prefixes C) in order with the substituent having the highest number of carbons first D) in order with the substituent having the lowest number of carbons first E) in order with the substituent having the highest total number of carbons first Answer: B 95) When drawing a structural formula, the first step is to draw A) the substituents. B) the most highly substituted carbons. C) the saturated carbons. D) the main carbon chain. E) the functional group. Answer: D 11.2 True/False Questions 1) Organic chemistry is the study of the chemistry of carbon compounds. Answer: TRUE 2) There are millions of organic compounds. Answer: TRUE 3) Carbon has six valence electrons. Answer: FALSE 4) Methane has a tetrahedral structure. Answer: TRUE 5) The bond angles in a tetrahedral molecule are 90°. Answer: FALSE 6) The difference in electronegativity between two atoms in a molecule determines the bond polarity. Answer: TRUE 7) Organic compounds are always highly water soluble. Answer: FALSE 8) Most organic compounds are flammable. Answer: TRUE 9) Amines contain carbon, hydrogen, and oxygen. Answer: FALSE 10) Pentane contains six carbon atoms. Answer: FALSE 11) Isomers have the same molecular formula. Answer: TRUE 12) The products of complete combustion are carbon dioxide and water. Answer: TRUE 19 13) Amines contain the functional group -OH. Answer: FALSE 14) Organic liquids are often lighter than water. Answer: TRUE 15) Most prescription drugs are organic molecules. Answer: TRUE 16) Functional groups are groups of atoms that act in predictable ways. Answer: TRUE 17) Functional groups always contain atoms other than just carbon and hydrogen. Answer: FALSE 18) Organic compounds can only be made by living things because a "vital force" is needed for their creation. Answer: FALSE 19) When naming an alkane, the main chain is the longest continuous carbon chain regardless of bends. Answer: TRUE 20) Octane is a seven-carbon linear alkane. Answer: FALSE 21) The first four linear alkyl substituent groups are named methyl, ethyl, propyl, and butyl. Answer: TRUE 22) Mineral oil is a liquid hydrocarbon used as a laxative and lubricant in medical practice. Answer: TRUE 23) Solid alkanes are found on the surface of many fruits and vegetables. Answer: TRUE 11.3 Matching Questions Identify the following as more characteristic of an organic compound or an inorganic compound. 1) high melting point A) organic 2) flammable B) inorganic 3) covalent bonds 4) insoluble in water 5) ionic bonds 1) B 2) A 3) A 4) A 20 5) B Match the following organic structures with the appropriate family name. 6) CH3CH2CH= CH2 A) aldehyde 7) B) amine O || CH3-C- CH3 C) thiol 8) CH3OH 9) O || CH3CH2COH D) amide E) carboxylic acid F) alkyne 10) CH3 CH2O CH2 CH3 G) haloalkane 11) H) ketone I) alkene O || CH3CO CH2CH3 12) CH3CH2SH J) ester K) ether 13) L) alcohol O || CH3CH2CH 14) HC≡CCH3 15) CH3CH2NH2 16) O || CH3CH2C NH2 17) Br | CH3CH CH3 6) I 12) C 7) H 13) A 8) L 14) F 9) E 15) B 21 10) K 16) D 11) J 17) G