Answer
The functional group in dipicolonic acid is carboxyl. In the figure on page 44, there are two carboxyl groups illustrated.
Work Step by Step
1. A carboxyl group is composed of one carbon, two oxygen, and one hydrogen.
2. It can be rendered as either -COOH or -CO2H.
3. In the figure on page 44, there are two carboxyl groups evident in the dipicolinic acid structure - on the top left and the top right respectively.
4. It makes sense that these would be present in dipicolinic acid, as carboxyl groups are present in molecules which are acidic by virtue of their being a source of hydrogen ions.
