. . "Mass fraction is used in the construction mass_fraction_of_X_in_Y, where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. The chemical formula for acetic_acid is CH3COOH. The IUPAC name for acetic acid is ethanoic acid."@en . "2009-07-06 15:41:29.0" . "SDN:P07::CF12N326" . "1" . "false" . "SDN:P07::CF12N326" . "mass_fraction_of_acetic_acid_in_air"@en . "SDN:P07::CF12N326" . "2009-07-06 15:41:29.0" . . . "accepted"@en . . . "1" . . "" .