Identify the empirical formula of mesitylene. This is a combustion reaction. All the carbon in the CO2 formed comes from the sample. Mesitylene is a liquid hydrocarbon. Burning the 0.115 g of the compound forms 0.1035 g of water and 0.379 g of CO2. All the hydrogen in the water formed comes from the sample. Hydrocarbons are binary compounds, made only of hydrogen and carbon.