2. Combustion ____________________ ____________________ ____________________

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

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

5. Complete Combustion • Complete Combustion occurs when O2 is __________ • It releases the ____energy and the __________ flames • General Equation: CXHY + O2(g) CO2(g) + H2O(g) + energy

6. Incomplete Combustion • Incomplete Combustion occurs when O2 is in __________ __________ • It releases _____energy and results in __________, sooty, yellow, cooler flames • Products (in addition to CO2 and H2O) • CO(g) (__________) • C(s) (soot, ash, _____of solid carbon products)

7. Problems of Incomplete Combustion • __________;releases only a portion of the energy contained in the fuel • city/highway/idle • __________; many chemicals in soot are toxic when inhaled, also builds up around engine • __________;- mistaken for O2 by hemoglobin in blood

8. Combustion Concerns • CO2 and H2O are greenhouse gases; contributing to _________ _________ • Many fuels contain __________ such as sulfur and heavy metals that contribute to air pollution • Firefighters • Forest Fires

9. Catalytic Converter 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 Without catalytic conversion Catalytic conversion Further reaction in the atmosphere Formation of acids in the atmosphere