Chapter 22

Which of the following structures are possible, given the numbers of bonds that various atoms normally form? (a) \(\mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{CHCH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{2} \mathrm{CH}_{3}\)

In \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{2}\), the \(\mathrm{NH}_{2}\) group is called the functional group. In general terms, why is it called this?

What must be true about two substances if they are to be called isomers of each other?

In general terms, why do functional groups impart more chemical reactivity to molecules that have them? Why don't the alkanes display as many reactions as, say, the amines?

Write the condensed structures of the following compounds: (a) 2,2 -dimethyloctane (b) 1,3 -dimethylcyclopentane (c) 1,1 -diethylcyclohexane (d) 6 -ethyl-5-isopropyl-7-methyloct-1-ene (e) cis-pent-2-ene

No number is needed to identify the location of the double bond in \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}_{2}\), propene. Why?

The compound but- 2 -ene exists as two isomers, but when both isomers are hydrogenated, the products are identical. Explain.

In general terms, why doesn't benzene undergo the same kinds of addition reactions as cyclohexene?

What is the difference between a substitution reaction and an addition reaction?

Why do aldehydes and ketones have boiling points that are lower than those of their corresponding alcohols?

Methyl ethanoate has many more atoms than its parent acid, ethanoic acid. Yet methyl ethanoate (BP \(59^{\circ} \mathrm{C}\) ) boils at a much lower temperature than ethanoic acid (BP \(118^{\circ} \mathrm{C}\) ). How can this be explained?

Write condensed structures of the following compounds: (a) 3 -methylbutanal (c) 2 -chloropropanoic acid (b) 4 -methyloctan- 2 -one (d) 1 -methylethylethanoate

Write condensed structures of the following compounds: (a) butan-2,3-dione (b) butanedicarboxylic acid (c) 2 -aminopropanal (d) cyclohexyl 2 -methylpropanoate

Briefly explain how the \(\mathrm{C}-\mathrm{O}\) bond in isopropyl alcohol is weakened when a strong acid is present.

Which isomer of butanol cannot be oxidized by dichromate ion? Write its structure and IUPAC name.

A monofunctional organic oxygen compound dissolves in aqueous base but not in aqueous acid. The compound is in which of the families of organic compounds that we studied? Explain.

Write the equation for the equilibrium that is present in a solution of propanoic acid and methanol with a trace of strong acid.

A monofunctional organic nitrogen compound dissolves in aqueous hydrochloric acid but not in aqueous sodium hydroxide. What kind of organic compound is it?

Why are aqueous solutions of amides neutral while amines are basic?

Hydrazine is a Brønsted base but urea does not exhibit basic properties. Offer an explanation.

Write the products that can be expected to form in the following situations. If no reaction occurs, write "no reaction." (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}+\operatorname{HBr}(a q) \longrightarrow\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}+\mathrm{HI}(a q) \longrightarrow\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{3}^{+}+\mathrm{H}_{3} \mathrm{O}^{+} \longrightarrow\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{3}^{+}+\mathrm{OH}^{-} \longrightarrow\)

What is a macromolecule? Name two naturally occurring macromolecular substances.

What is a polymer? Are all macromolecules polymers?

What do we mean by the term polymer backbone?

How do propylene and the repeating unit in polypropylene differ?

What is the difference between an addition polymer and condensation polymer?

What is the repeating unit in polypropylene? Write the formula for the polypropylene polymer. Give three uses for polypropylene.

Write the structure of polystyrene showing three of the repeating units. What are three uses for polystyrene plastic?

What is a copolymer?

Write the structural formula for (a) nylon 6,6 and (b) poly(ethylene terephthalate).

What are some applications of crystalline polymers such as HDPE, UHMWPE, and Kevlar?

What are the three fundamental needs for sustaining life, and what are the general names for the substances that supply these needs?

How are carbohydrates defined?

What monosaccharide forms when the following polysaccharides are completely hydrolyzed? (a) starch, (b) glycogen, (c) cellulose

Name the compounds that form when sucrose is digested.

The digestion of lactose gives what compounds? Name them.

The complete hydrolysis of the following compounds gives what product(s)? (Give the names only.) (a) amylose (b) amylopectin

Describe the relationships among amylose, amylopectin, and starch.

Why are humans unable to use cellulose as a source of glucose?

What function is served by glycogen in the body?

How are lipids defined?

Why are lipids more soluble than carbohydrates in nonpolar solvents?

What is the peptide bond? How is it similar to the amide bond in nylon?

Describe the structural way in which two isomeric polypeptides would be different.

Describe the structural ways in which two different polypeptides can differ.

Why is a distinction made between the terms polypeptide and protein?

What kind of substance makes up most enzymes?

In general terms only, how does the body solve the problem of getting a particular amino acid sequence, rather than a mixture of randomly organized sequences, into a polypeptide?

What kind of attractive force occurs between the two DNA strands in a double helix?

How are the two DNA strands in a double helix structurally related?