"2009-07-06 15:41:29.0" . . . . "SDN:P07::CF12N251" . "" . "accepted"@en . "2009-07-06 15:41:29.0" . "1" . "false" . . . "SDN:P07::CF12N251" . . . "SDN:P07::CF12N251" . . "1" . "mass_concentration_of_dinitrogen_pentoxide_in_air"@en . "Mass concentration means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. 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 dinitrogen pentoxide is N2O5."@en .