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Chapter 16
An Introduction to Carbonyl
and Carboxyl Compounds
CHEM 2124 – General Chemistry II
Alfred State College
Professor Bensley
Learning Objectives
 Identify the characteristics of aldehydes,
ketones, and carboxylic acids.
 Name aldehydes, ketones, and carboxylic
acids.
 Give examples of usefule aldehydes,
ketones, and carboxylic acids.
 Identify and prepare hemiacetals and
acetals.
Carbonyl and Carboxyl Compounds
I. Structure, Bonding, and Physical Properties
Carbonyl and Carboxyl Compounds
C. Bond Angles, Polarity
D. Boiling Points/Melting Points/Hydrogen Bonding
CH3CH2CH2CH2CH3
pentane
bp 36 oC
CH3CH2CH2CHO
butanal
bp 76 oC
Increasing boiling point
Carbonyl and Carboxyl Compounds
CH3CH2COCH3
2-butanone
bp 80 oC
CH3CH2CH2CH2OH
1-butanol
bp 118 oC
Increasing boiling point
Increasing boiling point
E. Solubility
Carbonyl and Carboxyl Compounds
II. Nomenclature
A. Aldehydes
CH3
CH3CHCH C
3 2
CH3
formaldehyde
butane  butanal
O
1
H
Answer:
2,3-dimethylbutanal
acetaldehyde
benzaldehyde
Carbonyl and Carboxyl Compounds
B. Ketones
O
CH3 C
pentane  pentanone
CHCH2CH3
CH3
1
2
acetone
Answer:
3-methyl-2-pentanone
3
acetophenone
benzophenone
Carbonyl and Carboxyl Compounds
C. Carboxylic Acids
CH3
O
CH3CHCHCH2CH2C OH
5 4
CH3
formic acid
1
hexane  hexanoic acid
Answer:
4,5-dimethylhexanoic acid
acetic acid
benzoic acid
Carbonyl and Carboxyl Compounds
III. Interesting Carbonyl Compounds
Formaldehyde (CH2═O) is the simplest aldehyde:
•It is sold as formalin, a 37%
aqueous solution used
to preserve biological
specimens.
Carbonyl and Carboxyl Compounds
Acetone [(CH3)2C═O] is the simplest ketone
Formic acid (HCO2H)
Acetic acid (CH3CO2H)
Hexanoic acid [(CH3(CH2)4COOH)]
Carbonyl and Carboxyl Compounds
IV.
Acetal and Hemiacetal Formation
Aldehydes undergo addition reactions
with alcohols to form hemiacetals and
acetals (in the presence of H2SO4).
Carbonyl and Carboxyl Compounds
•Cyclic hemiacetals containing 5 or 6 membered
rings are stable compounds.
Carbonyl and Carboxyl Compounds
•Cyclic hemiacetals are converted
to cyclic acetals by reaction
with another alcohol.