1. The combustion of the paraffin oil, which is a highly refined fossil fuel product similar to kerosene composed of C14-C16 hydrocarbons, resulted in the accumulation of black soot on the glass cylinder of you Stirling engine. When hydrocarbons are burned, some of the hydrocarbons do not fully react with the oxygen, and a complex range of compounds including PAHs (polycyclic aromatic hydrocarbons) are created. There is a strong correlation between the length of the hydrocarbon chain, and the amount of soot produced during burning. For instance, burning fuels with long chain hydrocarbons such as heavy fuel oil or diesel fuel produces a lot more soot than burning fuels with shorter chain hydrocarbons such as gasoline or propane. Use molecular diagrams to explain this phenomenon.