Download Chapter 12 Alcohols, Phenols, Ethers, Aldehydes

Chapter 13 Alcohols, Phenols, and
Thiols
13.3
Physical Properties of Alcohols,
Phenols, and Ethers
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
1
Boiling Points of Alcohols
Alcohols
 contain a strongly
electronegative O in the OH
groups
 form hydrogen bonds
between alcohol molecules
 have higher boiling points
than alkanes and ethers of
similar mass
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
2
Boiling Points of Ethers
Ethers
 have an O atom, but
no H is attached
 cannot form hydrogen
bonds between ether
molecules
 have boiling points
similar to alkanes of
similar mass
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
3
Solubility of Alcohols and Ethers
in Water
 Alcohols and ethers are more soluble in water than
are alkanes because the oxygen atom hydrogen
bonds with water.
 Alcohols with 1–4 C atoms are soluble, but alcohols
with 5 or more C atoms are not.
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
4
Comparing Solubility and Boiling
Points
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
5
Solubility of Phenol
Phenol
 is soluble in water
 has a hydroxyl group that ionizes slightly (so is a
weak acid)
 is corrosive and irritating to the skin
OH
O-
+ H2O
General, Organic, and Biological Chemistry
+ H3O+
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6
Learning Check
Which compound would have the higher boiling
point, ethyl methyl ether or 1-propanol? Explain.
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
7
Solution
Which compound would have the higher boiling
point, ethyl methyl ether or 1-propanol? Explain.
1-propanol would have the higher boiling point because
alcohol molecules can form hydrogen bonds, but ether
molecules cannot.
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
8
Learning Check
Which compound would be more soluble in water,
ethanol or 2-pentanol? Explain.
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
9
Solution
Which compound would be more soluble in water,
ethanol or 2-pentanol? Explain.
Ethanol. An alcohol with two carbons in its chain
is more soluble than one with 5 carbons. The longer
alkyl chain diminishes the effect of the –OH group.
General, Organic, and Biological Chemistry
Copyright © 2010 Pearson Education, Inc.
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