. . . . . . . . . "SDN:P07::CFV8N33" . "" . "mole_fraction_of_hydrogen_chloride_in_air"@en . "accepted"@en . "Mole fraction is used in the construction mole_fraction_of_X_in_Y, where X is a material constituent of Y. The chemical formula of hydrogen chloride is HCl."@en . . .