Ch. 14 – Carboxylic Acids and Their Derivatives
Carboxylic acids include the carboxyl group (-COOH or –CO
H), a carbonyl group bonded
to a hydroxyl group.
Many have common names widely used before IUPAC.
IUPAC method – 1) Find the LCC including the carboxyl group, and the C atom with the 2
O atoms is the #1 carbon (no # is needed to identify it, just like for aldehydes, cycloalcohols,
of the parent alkane and add
For a cycloalkane, the suffix
is added to the name of the cycloalkane.
If more than one –COOH group, the appropriate prefix is used before the
with two carboxyl groups, the ending is
The #’s of the C atoms with carboxyl groups
are included in the name.
Substituents are named, alphabetized and numbered as indicated in 1).
Most aromatic carboxylic acids are named as derived from benzoic acid.
Review Table 14.1 (p. 453) to compare the common names of some common carboxylic
acids with their IUPAC names in parentheses, along with their sources and the roots of their
You are expected to know the first four on this list (formic, acetic, propionic,
Physical Properties of Carboxylic Acids
Carboxylic acids with low MW’s are liquids at room temperature, and have sharp,
Butanoic acid (butyric acid) produces the odor of rancid butter and is
present in sweat (“locker room smell”).
As the MW increases, the acid becomes more waxy solids.
Octadecanoic acid (18 C’s total,
also stearic acid) is a key component in most candles.
Carboxylic acids have the highest BP’s of all the organic compounds that we have studied to
This is due to the following:
a) there is very strong intermolecular attraction as H-bonding exists in a way similar to
alcohols, and they are polar.
two H-bonds can be formed in –COOH compounds, as this dimer (a two-molecule unit)
acts often as a single particle.
The –COOH group readily H-bonds to water, so the first four carboxylic acids are
completely soluble in water, but then with increasing length of the carbon chain, the
solubility starts to markedly drop off.