ETS Major Field Test Chemistry Practice Test 2025 - Free Chemistry Practice Questions and Study Guide

Nuclear Magnetic Resonance (NMR) Spectrometry is a powerful analytical technique primarily used to determine the structure of organic compounds. It works by exposing nuclei of certain atoms, commonly hydrogen and carbon, to a magnetic field and radiofrequency radiation. The way these nuclei resonate provides detailed information about the environment surrounding them.

The correct choice indicates that NMR helps identify the number of different types of hydrogens or carbons in a compound. By analyzing the NMR spectrum, chemists can discern how many distinct hydrogen or carbon environments exist in a molecule, which is crucial for understanding its functional groups and overall structure. Each unique environment produces a distinct signal in the spectrum, allowing researchers to deduce structural details that are essential for molecular identification.

In contrast, NMR is not typically used to determine boiling points, molecular weights, or reactivities of compounds, as those properties require different methods of analysis such as gas chromatography, mass spectrometry, or kinetic studies.