Transcript CH_12_2_Properties_Alcohols_Ethers

Chapter 12 Organic Compounds with
Oxygen and Sulfur
1
12.2
Properties of Alcohols and Ethers
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Classification of Alcohols
2
Classification of alcohols is
• determined by the number of alkyl groups attached to the
carbon bonded to the hydroxyl
• primary (1), secondary (2), or tertiary (3)
Primary (1)
1 group
H
|
CH3—C—OH
|
H
Secondary (2)
2 groups
CH3
|
CH3—C—OH
|
H
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Tertiary (3)
3 groups
CH3
|
CH3—C—OH
|
CH3
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Learning Check
3
Classify each alcohol as primary, secondary, or tertiary.
OH
|
A. CH3—CH—CH2—CH3
B. CH3—CH2—CH2—OH
OH
|
C. CH3—CH2—C—CH2—CH3
|
CH3
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Solution
4
OH
|
A. CH3—CH—CH2—CH3
secondary
B. CH3—CH2—CH2—OH
primary
OH
|
C. CH3—CH2—C—CH2—CH3
|
CH3
tertiary
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Solubility of Alcohols in Water
5
Alcohols
• contain polar OH groups and
form hydrogen bonds with other
alcohol molecules
• that have one to three carbons are
soluble in water
• solubility in water decreases with
increasing number of carbons
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Solubility of Ethers in Water
6
Ethers
• do not have a polar OH group,
but have a COC group
• do not form hydrogen bonds
• with less than four carbons are
slightly soluble in water
• with more than four carbons are
not soluble in water
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Solubility of Alcohols and Ethers in
Water
7
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Solubility of Phenols
8
Phenols
• are slightly soluble in water
• have an OH group that can form hydrogen bonds with water
• can react with water to produce phenoxide ions
• were once used as antiseptics
OH
O-
+ H2O
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
+ H3O+
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Learning Check
9
Indicate whether each of the following is soluble in water
and explain why.
A. CH3CH2CH2CH2CH2CH2OH
B. CH3OCH2CH3
C. CH3CH2OH
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.
Solution
10
Indicate whether each of the following is soluble in water
and explain why.
A. CH3CH2CH2CH2CH2CH2OH
Not soluble
Alcohols with long carbon chains (nonpolar) are not soluble.
B. CH3OCH2CH3
Slightly soluble
Ethers with less than four carbons are only slightly
soluble in water.
C. CH3CH2OH
Soluble
Short-chain alcohols form hydrogen bonds with water.
Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition
Copyright © 2012 by Pearson Education, Inc.