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River Dell High School Team B Sharon Galperin Young Kim David Lo ENTHALPY OF FORMATION THE COMBUSTION OF AN ETHANOL- FUELED REACTOR Slide 2 PURPOSE Understand how enthalpy of formation is used Determine thermochemical properties of reactor, fuel, and oxidant: Enthalpy of reaction H rxn Standard enthalpy of formation of ethanol H f Structure of fuel Temperature changes Slide 3 ENTHALPY H = U+PV H, enthalpy U, internal energy P, pressure V, volume Enthalpy of Formation, H f Enthalpy of Combustion, H comb H rxn = H f (products) - H f (reactants) Slide 4 ETHANOL (C 2 H 5 OH) Grain alcohol Renewable liquid biofuel Alternative fuel source to gasoline Made from starch or sugar-based feedstocks Strongly resists knocking behavior with 100 ON in Spark Ignition (SI) Engines in automobiles Slide 5 ETHANOL (CONT.) Intermolecular Forces London Dispersion Forces Dipole-dipole Hydrogen-bonding Asymmetric molecule Polar (Bond triangle) Require higher activation energy (E act ) Slide 6 MATERIALS Reaction Chamber Tesla Coil Cork Slide 7 CALCULATIONS X = V ix t V y = V iy +a y t (equation 3) (equation 1) (equation 2) ViVi V ix V iy (Resolution of Vectors) Slide 8 DATA TABLE 1: KINETIC ENERGY TrialMass of cork (g) Volume of ethanol (mL) Distance traveled (Meters) V i (m/s) KE (J) % error 112.130.208.24010.980.73 99.95 211.850.2011.0412.810.97 99.93 312.040.2010.6312.560.95 99.93 411.820.2014.9214.971.33 99.91 511.970.2017.2216.121.56 99.89 Average11.960.2012.4113.491.11 99.92 Slide 9 DATA TABLE 2: TEMPERATURE CHANGE TrialMass of cork (g) Volume of Ethanol (mL) T initial (K) T final (K) T (K) 111.900.229731316 211.920.229731316 311.830.2297.731113.3 411.950.229831214 511.660.229830911 Average11.850.2297.5311.614.1 Slide 10 FINAL ASSUMPTIONS BASED ON EXPERIMENTAL DATA All energy released is transferred to cork Only 0.08% was transferred to cork Inefficiencies Friction Aerodynamic drag Sound Energy Thermal Energy Absorbed by Nalgene bottle Electromagnetic Energy Observe blue flame (Visible Light ) Slide 11 FINAL ASSUMPTIONS FROM EXPERIMENTAL DATA (CONT.) Complete Combustion Limiting reactant O 2 Incomplete Combustion C 2 H 5 OH +2O 2 2CO + 3H 2 O Slide 12 Enthalpy of formation in industry Energy efficiency CONCLUSIONS: Slide 13 CITATIONS: Slide 4 - http://perc.org/articles/should-congress-end- ethanol-subsidies (accessed May 1, 2013).http://perc.org/articles/should-congress-end- ethanol-subsidies Slide 4 - http://www.annualreviews.org.proxy1.library.mcgill.ca/doi/f ull/10.1146/annurev-physchem-040412-110009 (accessed May 1, 2013). http://www.annualreviews.org.proxy1.library.mcgill.ca/doi/f ull/10.1146/annurev-physchem-040412-110009 Slide 5 - http://www.metasynthesis.com/webbook/37_ak/ triangles.html (accessed May 1, 2013).http://www.metasynthesis.com/webbook/37_ak/ triangles.html Slide 12 - http://www.international-issues.org/the-khilafahs- energy-policy/ (accessed May 1, 2013).http://www.international-issues.org/the-khilafahs- energy-policy/