an herbicide contains only c , h , cl , and n . the complete combustion of a 100.0 mg sample of the herbicide in excess oxygen produced 104.6 ml of co2 and 61.01 ml of h2o vapor at stp. a separate analysis determined the 100.0 mg sample contained 27.57 mg cl . determine the percent composition of the herbicide. percent carbon: % percent hydrogen: % percent chlorine: % percent nitrogen: % determine the empirical formula of the herbicide. empirical formula: the herbicide has a molar mass of 257.16 g/mol . what is the molecular formula of the herbicide? molecular formula: