Chapter 22

Explain what is special about the element carbon that causes it to have such an extensive chemistry.

Why are alkanes also called saturated bydrocarbons? What is the hybridization of the carbon atoms in alkanes?

What are the hybridized orbitals on the carbon atoms that form the \(\sigma\) bonds in ethylene and acetylene?

Explain why cis and trans isomers exist for 1,2 -dibromoethene but not for 1,1 -dibromoethene.

Both carboxylic acids and alcohols contain the -OH functional group, but only one of them is acidic in water. Which one is acidic? Why?

Explain why ethyl alcohol has a higher boiling point than methyl ethyl ether even though the latter has the greater molecular weight.

Explain what is meant by cross-linking a polymer. How does cross-linking affect the properties of the polymer?

Describe the four levels of structure of a protein.

Describe the bonding in an \(\alpha\) -helix and in a \(\beta\) -pleated sheet. To what type of structure within the protein do these arrangements refer?

Describe the difference between cellulose and starch. How are they treated differently by the human digestive system?

Discuss the functions of DNA and RNA.

Describe the three components of a nucleotide. Be specific about the components used in DNA and those in RNA.

Describe the Watson and Crick model of DNA. How does this model account for the experimental fact that the \(\mathrm{A} / \mathrm{T}\) and \(\mathrm{G} / \mathrm{C}\) ratios are \(1 ?\)

Describe how both DNA and RNA are used in the synthesis of a specific protein.

Which of the following molecules are noncyclic alkanes? (a) \(\mathrm{C}_{8} \mathrm{H}_{16}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{14}\) (c) \(\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{~F}\) (d) \(\mathrm{C}_{9} \mathrm{H}_{20}\)

Which of the following molecules are noncyclic alkanes? (a) \(\mathrm{C}_{5} \mathrm{H}_{12}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{12}\) (c) \(\mathrm{C}_{3} \mathrm{H}_{6}\) (d) \(\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{Cl}\)

Write the molecular formula of a noncyclic alkane that contains eight carbon atoms.

Write the molecular formula of a noncyclic alkane that contains 12 carbon atoms.

Show a structural formula for the straight-chain isomer of \(\mathrm{C}_{5} \mathrm{H}_{12}\). Name the alkyl group formed by the removal of hydrogen atom from one of the terminal carbon atoms.

Show the structural formula for \(\mathrm{C}_{3} \mathrm{H}_{8}\). Name the alkyl group formed by the removal of a hydrogen atom from the center carbon atom.

Draw the structural formulas for the isomers of hexane, and name each isomer.

Draw structural formulas for possible isomers of the dichlorinated propane, \(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{Cl}_{2}\). Name each compound.

Write the structural formula for each of the following alkanes (a) 2 -methylhexane (b) 3,3 -dichloroheptane (c) 2 -methyl-3-phenyloctane (d) 1,1 -diethylcyclohexane

Write the structural formula for each of the following alkanes. (a) 1-bromobutane (b) 2 -methyl-3-nitropentane (c) 2,2 -dimethylhexane (d) 1 -chloro-1-methylcyclopentane

Write the general formulas for a noncyclic alkene and a noncyclic alkyne.

Show an example of an alkene that can exist as both cis and trans isomers and another that cannot.

Draw all possible isomers for the substituted alkene \(\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{~F}\)

Draw the structure, and give the systematic name for the products of the following reactions: (a) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}_{2}+\mathrm{Br}_{2} \rightarrow\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHCH}_{3}+\mathrm{H}_{2} \rightarrow\)

Write the structural formula for each of the following unsaturated compounds. (a) 2 -bromo-1-hexene (b) \(c i s-4\) -nitro- 2 -pentene (c) 1,2 -dichloro-3-hexyne (d) 1,1 -difluoro-3-chloro-1-heptene

Write the structural formula for each of the following unsaturated compounds. (a) 2,3 -dimethyl-1-pentene (b) 1 -methylcyclohexene (c) \(c i s-1-\) chloro- 2 -butene (d) 4 -methvl-1-hexene

Write the structural formula of propyne, and name the product of its reaction with two molecules of \(\mathrm{Cl}_{2}\).

Write the structural formula of 2 -hexene, and name the product of its reaction with \(\mathrm{Br}_{2}\).

Which of the following compounds can exist as cis and trans isomers? Draw and label them. (a) 2,3 -dimethyl-2-butene (b) 2 -chloro- 2 -butene (c) dichlorobenzene

Draw the three isomers of dimethylbenzene.

Draw all the isomers of trichlorobenzene.

Write the structural formula and name the organic product expected from the acid-catalyzed condensation reaction of \(\mathrm{CH}_{3} \mathrm{OH}\).

Write the structural formula and name the organic product expected from the mild air oxidation of \(\mathrm{CH}_{3} \mathrm{OH}\).

Write the structural formula and name the organic product expected from the acid-catalyzed condensation reaction of \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}\) and \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}\).

Aldehydes and carboxylic acids are formed by oxidation of primary alcohols, and ketones are formed when secondary alcohols are oxidized. Give the name and formula for the alcohol that, when oxidized, gives the following products. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CHO}\) (b) 2 -hexanone

Draw the structure of each of the following molecules. (a) 1 -butanol (b) 3 -methyl-2-pentanone (c) methyl acetate (d) ethylphenylamine

Draw the structure of each of the following molecules. (a) ethyl vinyl ether (b) 2 -bromopropanal (c) pentanoic acid (d) 3 -fluorophenol

Describe and give a specific example of the formation of (a) a chain-growth polymer. (b) a homopolymer.

Describe and give a specific example of the formation of (a) a step-growth polymer. (b) a copolymer.

Polyvinyl chloride, a chemically resistant polymer used in house siding and floor tiles, is a chain-growth polymer of chloroethene (vinyl chloride). Draw the repeating unit of polyvinyl chloride.

Polystyrene, a polymer used for thermal insulation (e.g., coolers) and toys, is a chain-growth polymer of phenylethylene (styrene). Draw the repeating unit of polystyrene.

Viton is a strong, flexible chain-growth copolymer used in gaskets. It is formed from 1,1 -difluoroethylene and hexafluoropropene. Draw the repeating unit.

Tires are frequently made from SBR, the trade name of the chain-growth copolymer made from styrene \(\left(\mathrm{CH}_{2}=\mathrm{CHC}_{6} \mathrm{H}_{5}\right)\) and butadiene \(\left(\mathrm{CH}_{2}=\mathrm{CHCH}=\mathrm{CH}_{2}\right)\) Draw the repeating unit.

Polyacrylonitrile, a chain-growth polymer used in carpets, is formulated as follows. What monomer is used to make polyacrylonitrile?

Write the general reaction for the combination of two amino acids to form a dipeptide.

Give the structural formula of two different dipeptides formed between arginine and serine.