What you’ll learn9 learning objectivesChoose one objective for a focused lesson, or study the complete topic.1.3.1Combustion reactions• Reactive metals, non-metals, organic compounds + O₂• Deduce complete combustion equations for hydrocarbons and alcoholsSyllabus objective1.3.2Incomplete combustion• Produces CO and C• Deduce incomplete combustion equations for hydrocarbons and alcoholsSyllabus objective1.3.3Fossil fuels• Coal, crude oil, natural gas• CO₂ emissions and greenhouse effect• Compare fuels by carbon dioxide released and energy outputSyllabus objective1.3.4Biofuels• From biological carbon fixation (photosynthesis)• Renewable vs. non-renewable• Consider advantages and disadvantages of biofuels compared with fossil fuelsSyllabus objective1.3.5Fuel cells• Convert chemical energy directly to electrical energy• Half-equations for electrode reactions• Include hydrogen and methanol fuel cells; PEM details are not assessedSyllabus objective1.4.1(HL)—Entropy (S)• Measure of dispersal of matter/energy• More energy distributions = higher entropy• Order: Sgas > Sliquid > Ssolid• Calculate ΔS⦵ from S⦵ valuesSyllabus objective1.4.2(HL)—Gibbs energy (ΔG)• ΔG⦵ = ΔH⦵ − TΔS⦵• Relates energy from reaction to ΔH, ΔS, TSyllabus objective1.4.3(HL)—Spontaneity• Spontaneous when ΔG < 0• Temperature at which reaction becomes spontaneous• Interpret signs of ΔG from thermodynamic dataSyllabus objective1.4.4(HL)—Equilibrium and Gibbs energy• At equilibrium: ΔG = 0• ΔG = ΔG⦵ + RT ln Q• ΔG⦵ = −RT ln K• Link ΔG, Q, and K to reaction direction and equilibrium positionSyllabus objective