Is stearic acid a monomer or polymer?

Answer 1

It wouldn't generally be considered as either a polymer or a monomer.

Stearic acid is a long chain (18 carbons long) carboxylic acid (sometimes known as "fatty acid"). Therefore its molecules are not sufficiently long to be considered a polymer, and there is no functionality along the carbon chain to enable polymerisation to take place, therefore it would not be classed as a monomer either.

Small molecules are only referred to as "monomers" in the context of their ability to link together with many other similar molecules to form polymers.

Note that it is possible to create polymers using certain carboxylic acids, but they need to have two carboxyl groups (reaction of dicarboxylic acids with diols creates polyesters by a condensation reaction). Stearic acid only contains one carboxyl group.