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Combustion ____________________

Hydrocarbon Combustion  Hydrocarbons are molecular (covalent) compounds made ____________________ ____________________  Many are used as fuels; _______________ ________________________________  Combustion reactions produce heat (_______________ ) & light (_______________ _______________ ) 3

Complete or Incomplete? 4  All hydrocarbons ______, provided they are ______enough and have sufficient ______  Depending on the products that form, we classify combustion as either __________or __________

Complete Combustion  Complete Combustion occurs when O 2 is __________  It releases the ____ energy and the __________ flames  General Equation: C X H Y + O 2(g)  CO 2(g) + H 2 O (g) + energy 5

Incomplete Combustion  Incomplete Combustion occurs when O 2 is in __________ __________  It releases _____ energy and results in __________, sooty, yellow, cooler flames  Products (in addition to CO 2 and H 2 O)  CO (g) ( __________ )  C (s) (soot, ash, _____ of solid carbon products) 6

Problems of Incomplete Combustion 1) __________; releases only a portion of the energy contained in the fuel  city/highway/idle 2) __________ ; many chemicals in soot are toxic when inhaled, also builds up around engine 3) __________; - mistaken for O 2 by hemoglobin in blood 7

Combustion Concerns  CO 2 and H 2 O are greenhouse gases; contributing to _________ _________  Many fuels contain __________ such as sulfur and heavy metals that contribute to air pollution  Firefighters  Forest Fires 8

This diagram shows how the polluting effects of nitrogen combustion in vehicle engines can be largely eliminated by catalytic conversion. Match each chemical equation to the correct position in the diagram. Combustion in the engine Catalytic conversion Without catalytic conversion Further reaction in the atmosphere Formation of acids in the atmosphere Catalytic Converter