Acetic acid acid solutions: Concentrated acetic acid can be ignited only with difficulty at standard temperature and pressure, but becomes a flammable risk in temperatures greater than , and can form explosive mixtures with air at higher temperatures (explosive limits: 5.4–16%). Acetic acid Acetic acid , systematically named ethanoic acid , is a colourless liquid organic compound with the chemical formula CHCOOH (also written as CHCOH or CHO). When undiluted, it is sometimes called "glacial acetic acid". Vinegar is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. Acetic acid has a
Chemical compound for the chemical elements, and subscripts to indicate the number of atoms involved. For example, water is composed of two hydrogen atoms bonded to one oxygen atom: the chemical formula is HO. In the case of non-stoichiometric compounds, the proportions may be reproducible with regard to their preparation, and give fixed proportions of their component elements, but proportions that are not integral [e.g., for palladium hydride, PdH (0.02 < x < 0.58)]. Chemical compounds have a unique and defined chemical structure held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be molecular compounds held together by