Question

Prior to their phaseout in the 1980s, chemicals containing lead were commonly added to gasoline as anti-knocking agents. a 2.475 g sample of one such additive containing only lead, carbon, and hydrogen was burned in an oxygen rich environment. the products of the combustion were 2.694 g of co2(g) and 1.378 g of h2o(g). insert subscripts below to appropriately display the empirical formula of the gasoline additive:

Answer 1

4.007-2.694 g of CO2 = 2.694 x 12 / 44 g of C = 0.7347 g of C = 0.0911 moles of C 2.050-1.378 g of H2O = 2.050 x 2 / 18 g of H = 0.1531 g and 0.1531 moles mass of Pb = 2.475 - ( 0.0911 + 0.1531) g = 2.23 g = 2.23 / 207 = 0.0108 moles 
molar ratio of C:H:Pb = 0.0911: 0.1531: 0.0108divide by the smallest number and we get 8.0: 20.0: 1.0 
empirical formula is C8H20Pb 
tetraethyl lead