Answers and Explanations

DISCRETE PRACTICE QUESTIONS

1 . B

Alcohols    have    higher  boiling points  than    their   analogous   hydrocarbons    as  a   result  of  their

polarized   O–H bonds,  in  which   oxygen  is  partially   negative    and hydrogen    is  partially   positive.   This

enables the oxygen  atoms   of  other   alcohol molecules   to  be  attracted   to  the hydrogen,   forming a

hydrogen    bond.   Heat    is  required    to  overcome    these   hydrogen    bonds,  thereby increasing  the

boiling point.  The analogous   hydrocarbons    do  not form    hydrogen    bonds   and,    therefore,  vaporize

at  lower   temperatures.   Choice  (A) is  irrelevant; oxygen’s    bond    length  is  not a   factor  in

determining a   substance’s boiling point.  Choices (C) and (D) are true    statements, but are also

irrelevant  to  boiling point   determination.

2 . A
Tertiary alcohols can be oxidized but only under extreme conditions because their substrate
carbons do not have spare hydrogens to give up. Alcohol oxidation involves the removal of such a
hydrogen so that carbon can instead make another bond to oxygen. If no hydrogen is present, a
carbon–carbon bond must be cleaved, which requires a great deal of energy and will, therefore,
occur only under extreme conditions. Choice (B) is incorrect because alcohols are not carbonyl-
containing compounds and would more properly describe a carbonyl-containing compound that
is unable to form an enolate. Choice (C) is incorrect because the hydroxyl group of the tertiary
carbon is still polarized. Choice (D) is a false statement; tertiary alcohols are still involved in other
reactions, such as SN1 reactions.

3 . B
Remember, diols are named after the parent alkane, with the position of the alcohols indicated,
and ending in the suffix –diol. Here the carbon chain is three carbons, with a hydroxyl group on
carbons 1 and 2. Thus, the name is propane-1,2-diol.

4 . B