Question

A 4.236 g sample of a hydrocarbon is combusted to give 3.810 g of h2o and 13.96 g of co2. what is the empirical formula of the compound?

Answer 1

Given mass: 3.810 g of h2o and 13.96 g of co2. Mass of CO2 : 13.96 g moles of CO2 : 0.317 moles / 44.0098 moles of C : 0.317 moles Mass of water = 3.81 g moles of water = 0.212 moles / 18.015 moles of H = 0.423 moles X2 Hence the molar ratio C : H is 0.317 : 0.423 = 1.000 : 1.334 Multiplying by 3 on both ratios we get: 3.000 : 4.003 Therefore the empirical formula is C3H4