Organic Compound
＊Definition: Alcohol is organic compound in which ____________ is bond to a
carbon atom. The general formula for a simple alcohol containing no rings is
__________
＊Classification: Three major subsets of alcohols- 'primary' (1°), 'secondary' (2°) and
'tertiary' (3°), based upon the __________ the C-OH carbon is bonded to. A primary
(1°) alcohol is one in which the carbon atom with the OH group is attached to
__________. Its general formula is __________. A secondary (2°) alcohol is one in
which the carbon atom (in red) with the OH group is attached to __________ other
carbon atoms (in blue). Its general formula is __________. A tertiary (3°) alcohol is
one in which the carbon atom with the OH group is attached to __________ other
carbon atoms. Its general formula is __________.Is isobutyl alcohol primary,
secondary, or tertiary? __________
Methanol and ethanol: Methanol was formerly obtained by the distillation
of_______, and was called "wood alcohol". It is now a cheap commodity chemical.
Aside from ethanol’s major use in __________, ethanol is also used (though highly
controlled) as an __________ and raw material.
＊ Nomenclature: Common Names: Alcohols with__________ carbon atoms are
frequently called by common names, in which the name of the alkyl group is
followed by the word alcohol:
IUPAC System: alcohols are named by changing the ending of the parent alkane name
to ______. 1. The ____________________ of carbon atoms containing the OH group
is taken as the parent compound. The chain is numbered from the end _________ the
OH group. 2. The number that indicates the position of the OH group is placed
________ the name of the parent hydrocarbon, and separated by a _____. The
____ending of the parent alkane is replaced by the suffix ___. Substituents are named
and numbered as in alkanes. In _____ alcohols, the carbon atom bearing the OH
group is designated ___, but the 1 is not used in the name.3. If __________ OH group
appears in the ________________ (polyhydroxy alcohols), _________ such as -diol
and -triol are used. In these cases, the -e ending of the parent alkane is ________.
Draw the structure for the compound. 2-hexanol: 1. The ending____ indicates an
alcohol (the OH functional group), and the____ stem tells us that there are six carbon
atoms in the LCC. We start by drawing a ______ of six carbon atoms:
–C–C–C–C–C–C–. 2. The 2 indicates that the OH group is attached to __________
carbon atom. 3. Finally, we add enough__________ to give each carbon atom four
bonds.
1.
__________
2. 3-pentanol
__________
＊Properties: Alcohol is a general term denoting a family of organic chemicals with
common properties. Members of this family include
and others.
Most of the common alcohols are
at room temperature.
The
generally makes the alcohol molecule
and
in water, while the non-polar hydrocarbon chain tends to make alcohols insoluble.
Hydrogen bonding raises the
of alcohols. This is due to the
combined strength of so many hydrogen bonds forming between oxygen atoms of one
alcohol molecule and the hydroxy H atoms of another. The
the carbon chain
in an alcohol is, the
the solubility in
and the
the solubility
in
.
Practice：Arrange according to increasing boiling point. (start with lowest boiling
point)1. CH4, CH3OH, CH3CH3
Arrange according to increasing solubility (start with lowest solubility)
2. CH4, CH3CH2Cl, CH3CH2OH
Solution: CH4, CH3CH3, CH3OH ;CH3CH2Cl, CH4, CH3CH2OH
Solubility: The small alcohols are
in water. However, solubility
falls as the length of the hydrocarbon chain in the alcohol
. The
end
of the alcohol molecules can form new hydrogen bonds with water molecules, but the
hydrocarbon
doesn‘t form hydrogen bonds. So quite a lot of the original
hydrogen bonds being broken are replaced by
.
Chemical Properties: Deprotonation: Alcohols can behave as weak acids,
undergoing deprotonation. e.g. 2 CH3CH2-OH + 2 Na → 2 CH3-CH2-O−Na+
Toxicity: All alcohols are poisonous.
is no exception. While infrequent
consumption of ethanol in small quantities may be harmless or even beneficial, larger
doses result in drunkenness, and even can cause
, such as liver and
brain damage.
Exercises:
1. Name each alcohol and classify it as primary, secondary, or tertiary.
a. CH3CH2CH2CH2CH2CH2OH
b.
c.
2. Draw the structure for each alcohol.
a. 3-hexanol
b. 3,3-dimethyl-2-butanol
c. cyclobutanol
3. What is the general formula of a simple alcohol?
4. How to determine which kind of subset is an alcohol?
5. What makes the alcohol molecule polar ?
6. Which alcohol is less poisonous than other alcohols?