What is a common method for identifying unknown organic compounds?

NMR (Nuclear Magnetic Resonance) Spectroscopy is a powerful and widely used technique for identifying unknown organic compounds due to its ability to provide detailed information about the molecular structure. This method takes advantage of the magnetic properties of certain nuclei, such as hydrogen or carbon, when placed in a strong magnetic field. By analyzing the resulting spectrum, chemists can deduce the number of hydrogen atoms attached to each carbon atom in the molecule, the arrangement of the carbon skeleton, and the presence of functional groups.

The data obtained from NMR spectra allow for the determination of connectivity between atoms, including which hydrogen atoms are associated with which carbon atoms and even the presence of heteroatoms. This makes it an invaluable tool for structural elucidation. In contrast to other methods listed, such as evaporation, conductometric titration, and filtration, which provide limited or different types of information, NMR directly reveals molecular structure and dynamics, making it the method of choice for identifying unknown organic compounds.