Chapter 23

Polyvinyl acetate is the binder in water-based paints. (a) Write an equation for its formation from vinyl acetate. (b) Show a portion of this polymer with three monomer units. (c) Describe how to make polyvinyl alcohol from polyvinyl acetate.

Neoprene (polychloroprene, a kind of rubber) is a polymer formed from the chlorinated butadiene \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CHCCl}=\mathrm{CH}_{2}\) (a) Write an equation showing the formation of polychloroprene from the monomer. (b) Show a portion of this polymer with three monomer units.

Polyacrylonitrile is a polymer of acrylonitrile, \(\mathrm{CH}_{2}=\mathrm{CHCN} .\) Write an equation for the synthesis of this polymer.

Three different compounds with the formula \(\mathrm{C}_{2} \mathrm{H}_{2} \mathrm{Cl}_{2}\) are known. (a) Two of these compounds are geometric isomers. Draw their structures. (b) The third compound is a structural isomer of the other two. Draw its structure.

Draw the structure of 2-butanol. Identify the chiral carbon atom in this compound. Draw the mirror image of the structure you first drew. Are the two molecules superimposable?

An alkene having the formula \(\mathrm{C}_{6} \mathrm{H}_{12}\) is known to have a six-carbon chain. How many isomeric species can be drawn based on this description? List the names of these species.

Draw structures and name the four alkenes that have the formula \(\mathrm{C}_{4} \mathrm{H}_{8}\)

Write equations for the reactions of cis-2-butene with the following reagents, representing the reactants and products using structural formulas. (a) \(\mathrm{H}_{2} \mathrm{O}\) (b) HBr (c) \(\mathrm{Cl}_{2}\)

Draw the structure and name the product formed if the following alcohols are oxidized. Assume an excess of the oxidizing agent is used. If the alcohol is not expected to react with a chemical oxidizing agent, write NR (no reaction). (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (b) 2-butanol (c) 2 -methyl-2-propanol (d) 2 -methyl-1-propanol

Write equations for the following reactions, representing the reactants and products using structural formulas. (a) The reaction of acetic acid and sodium hydroxide (b) The reaction of methylamine with HCl

Write an equation for the formation of the following polymers. (a) Polystyrene, from styrene \(\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}=\mathrm{CH}_{2}\right)\) (b) PET (polyethylene terephthalate), from ethylene glycol and terephthalic acid

Write equations for the following reactions, representing the reactants and products using structural formulas. (a) The hydrolysis of the amide \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CONHCH}_{3}\) to form benzoic acid and methylamine (b) The hydrolysis of \(\left(-\mathrm{CO}\left(\mathrm{CH}_{2}\right)_{4} \mathrm{CONH}\left(\mathrm{CH}_{2}\right)_{6} \mathrm{NH}-\right)_{n}\) (nylon-6,6, a polyamide) to give a carboxylic acid and an amine

Draw the structure of each of the following compounds: (a) 2,2 -dimethylpentane (b) 3,3 -diethylpentane (c) 3-ethyl-2-methylpentane (d) 3 -ethylhexane

Structural isomers. (a) Draw all of the isomers possible for \(\mathrm{C}_{3} \mathrm{H}_{8} \mathrm{O}\) Give the systematic name of each, and tell into which class of compound it fits. (b) Draw the structural formulas for an aldehyde and a ketone with the molecular formula \(\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O} .\) Give the systematic name of each.

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

Draw structural formulas for possible isomers with the formula \(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{ClBr},\) and name each isomer.

Give structural formulas and systematic names for the three structural isomers of trimethylbenzene, \(\mathrm{C}_{6} \mathrm{H}_{3}\left(\mathrm{CH}_{3}\right)_{3}\)

Give structural formulas and systematic names for possible isomers of dichlorobenzene, \(\mathrm{C}_{6} \mathrm{H}_{4} \mathrm{Cl}_{2}.\)

Benzoic acid occurs in many berries. When humans eat berries, benzoic acid is converted to hippuric acid in the body by reaction with the amino acid glycine \(\mathrm{H}_{2} \mathrm{NCH}_{2} \mathrm{CO}_{2} \mathrm{H}\). Draw the structure of hippuric acid, knowing it is an amide formed by reaction of the carboxylic acid group of benzoic acid and the amino group of glycine. Why is hippuric acid referred to as an acid?

Consider the reaction of cis-2-butene with \(\mathrm{H}_{2}\) (in the presence of a catalyst). (a) Draw the structure, and give the name of the reaction product. Is this reaction product chiral? (b) Draw an isomer of the reaction product.

Draw the structure of glyceryl trilaurate, a fat. Lauric acid (page 941 ) has the formula \(\mathrm{C}_{11} \mathrm{H}_{23} \mathrm{CO}_{2} \mathrm{H}\) (a) Write an equation for the base hydrolysis of glyceryl trilaurate. (b) Write an equation for the reaction that could be used to prepare biodiesel fuel from this fat.

Identify the reaction products, and write an equation for the following reactions of \(\mathrm{CH}_{2}=\mathrm{CHCH}_{2} \mathrm{OH}.\) (a) \(\mathrm{H}_{2}\) (hydrogenation, in the presence of a catalyst (b) Oxidation (excess oxidizing agent) (c) Addition polymerization (d) Ester formation, using acetic acid

The product of an addition reaction of an alkene is often predicted by Markovnikov's rule. (a) Draw the structure of the product of adding HBr to propene, and give the name of the product. (b) Draw the structure and give the name of the compound that results from adding \(\mathrm{H}_{2} \mathrm{O}\) to 2-methyl-1-butene. (c) If you add \(\mathrm{H}_{2} \mathrm{O}\) to 2 -methyl- 2 -butene, is the product the same or different than the product from the reaction in part (b)?

There are three ethers with the formula \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}.\) Draw their structures.

Nylon-6 is a polyamide formed by polymerizing \(\mathrm{H}_{2} \mathrm{NCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CO}_{2} \mathrm{H} .\) Write an equation for this reaction.

You have a liquid that is either cyclohexene or benzene. When the liquid is exposed to dark-red bromine vapor, the vapor is immediately decolorized. What is the identity of the liquid? Write an equation for the chemical reaction that has occurred.

Hydrolysis of an unknown ester of butanoic acid, \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CO}_{2} \mathrm{R},\) produces an alcohol \(\mathrm{A}\) and butanoic acid. Oxidation of alcohol A forms an acid B that is a structural isomer of butanoic acid. Give the names and structures for alcohol \(A\) and acid B.

You are asked to identify an unknown colorless, liquid carbonyl compound. Analysis has determined that the formula for this unknown is \(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O} .\) Only two compounds match this formula. (a) Draw structures for the two possible compounds. (b) To decide which of the two structures is correct, you react the compound with an oxidizing agent and isolate from that reaction a compound that is found to give an acidic solution in water. Use this result to identify the structure of the unknown. (c) Name the compound formed by oxidation of the unknown.

Describe a simple chemical test to tell the difference between \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\) and its isomer cyclopentane.

Describe a simple chemical test to tell the difference between 2-propanol and its isomer methyl ethyl ether.

An unknown ester has the formula \(\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}_{2}\) Hydrolysis gives methanol as one product. Identify the ester, and write an equation for the hydrolysis reaction.

The transestification reaction between PET and \(\mathrm{CH}_{3} \mathrm{OH}\) forms dimethyl terephthalate and ethylene glycol. If the methanol used in this reaction is labeled with oxygen-18 \(\left(^{18} \mathrm{O}\right),\) in which of the products will the label be found?

Carbon atoms appear in organic compounds in several different ways with single, double, and triple bonds combining to give an octet configuration. Describe the various ways that carbon can bond to reach an octet, and give the name and draw the structure of a compound that illustrates that mode of bonding.

There is a high barrier to rotation around a carbon-carbon double bond, whereas the barrier to rotation around a carbon-carbon single bond is considerably smaller. Use the orbital overlap model of bonding (Chapter 9 ) to explain why there is restricted rotation around a double bond.

What important properties do the following characteristics impart to a polymer? (a) Cross-linking in polyethylene (b) The OH groups in polyvinyl alcohol (c) Hydrogen bonding in a polyamide like nylon

Maleic acid is prepared by the catalytic oxidation of benzene. It is a dicarboxylic acid; that is, it has two carboxylic acid groups. (a) Combustion of 0.125 g of the acid gives \(0.190 \mathrm{g}\) of \(\mathrm{CO}_{2}\) and \(0.0388 \mathrm{g}\) of \(\mathrm{H}_{2} \mathrm{O} .\) Calculate the empirical formula of the acid. (b) A 0.261-g sample of the acid requires \(34.60 \mathrm{mL}\) of \(0.130 \mathrm{M} \mathrm{NaOH}\) for complete titration (so that the H ions from both carboxylic acid groups are used). What is the molecular formula of the acid? (c) Draw a Lewis structure for the acid. (d) Describe the hybridization used by the C atoms (e) What are the bond angles around each C atom?