B. Organic Acids

1
B. Organic Acids
Second functional group
1. Carboxyl Group
-the functional group is the carboxyl group
O --C--OH
Notice how the C is double bonded to one oxygen
Since there is only one more bonding site, the
carboxyl group is always found on the end of a
chain
H H H O
H-C--C--C--C--OH H
H H
H
H
H
-

H
In solution, it is the H from the OH that is
creates the H
Always written as COOH at the end of the
molecular formula
H H H O
H-C--C--C--C--OH H
H H
C3
H7
COOH
This is how you recognize an organic acid
2
Practice - Write out the molecular formula for
the following
O H HO-C--C--H
H
H H O H-C--C--C--OH
H H
O H--C--OH
CH3COOH
HCOOH
C2H5COOH
2. Naming Organic Acids
Take the longest alkane chain, remove the e and
add
oic acid
O H--C--OH
Methanoic acid
Commonly called Formic acid
H O H-C--C--OH H
Commonly called Acetic acid
Ethanoic acid
3
Example - Name the following acids
H H O H-C--C--C--OH
H H
H H O H-C--C--C--OH
HCHH H
O H H Cl H
HO-C--C--C--C--C--H
H H Cl H
Propanoic acid
Butanoic acid
Pentanoic acid
4,4-dichloro