C3H5O2

C3H5O2 is a molecular formula that denotes a compound containing three carbon atoms, five hydrogen atoms, and two oxygen atoms. As written, the formula does not specify a unique molecule; multiple distinct isomers, including radical or ionic species, could fit the same composition. In practice, this formula is most often encountered for transient species, fragments in mass spectrometry, or in theoretical studies rather than as a single well-characterized stable compound.

Because two oxygen atoms are present, the formula could in principle accommodate several functional groups, such as carbonyl-containing fragments or ester- or peroxide-related motifs. However, without information on connectivity, charge, or hydrogen distribution, the exact identity—such as whether the species is neutral or charged, closed-shell or radical, and how the atoms are arranged—remains undetermined. Consequently, C3H5O2 is treated as an empirical or provisional formula rather than a definitive structural description.

In chemical databases and literature, C3H5O2 may be encountered in contexts that emphasize its role as a fragment or proposed intermediate rather than as a stand-alone, isolated compound. Related formulas illustrate the sensitivity of identity to hydrogen count: C3H6O2 corresponds to stable compounds such as propionic acid or ethyl formate, while C3H4O2 relates to other unsaturated carboxyl-containing species. These relationships underscore how small changes in composition can lead to markedly different structures and properties.

See also: molecular formula, isomerism, radical species, mass spectrometry.