Which method is primarily used to identify functional groups in organic compounds?

Functional group testing is a method specifically designed to detect the presence of particular functional groups in organic compounds. This approach typically involves adding certain reagents that will react with specific functional groups, resulting in observable changes, such as color changes or the formation of precipitates. Each type of functional group—like alcohols, aldehydes, ketones, and carboxylic acids—has characteristic reactions that can be used as indicators.

While mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy provide valuable information about the overall structure and composition of a compound, they do not specifically target functional group identification in a straightforward manner. Mass spectrometry offers insights into the molecular weight and fragmentation patterns, and NMR gives information on the environment of nuclei within the molecule, both of which can suggest functional groups but do not clearly define them. Infrared spectroscopy, on the other hand, is indeed used to identify functional groups based on molecular vibrations; however, functional group testing is a more direct and targeted approach for this purpose. Thus, functional group testing stands out as the primary method for identifying functional groups in organic compounds.