1.Video Tutorial on Entropy, Second Law ofThermodynamics and Spontaneity. Prepared by Lawrence Kok http://lawrencekok.blogspot.com

2. Video on Entropy and Free EnergyEntropy from Khan Academy Entropy calculation from Khan Academy Video on Gibbs Free Energy Entropy explained using microstates 3. Entropy and SpontaneityEntropy Measures the degree of DISORDER for a system Measures the probability or chance for a system, both in distribution of particles in spaceand distribution of energy How will a reaction go ? Why gas MIXES and NOT UNMIX ? Why concentrated solute DIFFUSE and NOT UNDIFFUSE? 4. Entropy and SpontaneityImportant concepts for Entropy Unit for entropy JK-1mol-1 Formula for entropy, S = k ln W k = Boltzmann constantW = Number ways a particle can arrange in space Absolute entropy can be measured! Entropy of a perfectly order solid crystal at OK is ZERO Entropy of an element under standard condition is NOT ZEROS (H2) gas = 130.6JK-1mol-1 Standard entropy change, S = Entropy change per mole of a substanceheated from OK to standard Temp of 298K 5. Entropy and SpontaneityENTROPY CHANGE, S Change in the disorder of a system Higher disorder Higher entropy Change in state from SOLID LIQUID GAS Higher entropy Greater number of particles formed in products Higher entropy Complex molecules (more atoms bonded) Higher entropy Higher temperature Particles vibrate faster More random Higher entropy Standard entropy, S /298K S / JK-1mol-1 6. Second Law of Thermodynamics For all spontaneous reactions, TOTAL entropy of the universe S (uni) always INCREASES Formula for Ssys = S (products) - S (reactants) Formula for S (surrounding) Reaction will be spontaneous if - Conclusion : For spontaneous reaction, S (uni) must > O (positive) 7. Using H and S to predict if reaction is spontaneous at 298KSsysSsurrounding+ 8. Using H and S to predict if reaction is spontaneous at 298KSsys Ssurrounding +S universe 9. Using H and S to predict if reaction is spontaneous at 298KSsys Ssurrounding +S universeConclusion : Spontaneous - Entropy of system S sys DECREASES BUTheat released to the surrounding INCREASES the entropy of surrounding, S surrounding 10. Using H and S to predict if reaction is spontaneous at 298KSsysSsurrounding+ 11. Using H and S to predict if reaction is spontaneous at 298KSsysSsurrounding+S universe 12. Using H and S to predict if reaction is spontaneous at 298KSsysSsurrounding+S universeConclusion : Spontaneous - Entropy of system S sys DECREASES BUTheat released to the surrounding INCREASES the entropy of surrounding, S surrounding 13. Using H and S to predict if reaction is spontaneous at 298KSsysSsurrounding+ 14. Using H and S to predict if reaction is spontaneous at 298KSsysSsurrounding+S universe 15. Using H and S to predict if reaction is spontaneous at 298KSsys Ssurrounding + S universeConclusion : Non Spontaneous - Entropy of system S sys INCREASES BUTheat absorbed from surrounding DECREASES the entropy of surrounding, S surrounding 16. Using H and S to predict if reaction is spontaneous at 298K Is it possible to freeze water at 298K ( 25oC)At 25oCSsys Ssurrounding + 17. Using H and S to predict if reaction is spontaneous at 298K Is it possible to freeze water at 298K ( 25oC)At 25oCSsys Ssurrounding + S universe 18. Using H and S to predict if reaction is spontaneous at 298K Is it possible to freeze water at 298K ( 25oC)At 25oC SsysSsurrounding + S universeConclusion : Non Spontaneous - Entropy of system S sys DECREASES more than >the INCREASE in entropy of surr, S surr due to heat released to the surroundingresulting in a NET DECREASE in Total Entropy of universe 19. Using H and S to predict if reaction is spontaneous at 263KIs it possible to freeze water at 263K ( -10oC)At -10oC Ssys Ssurrounding+ 20. Using H and S to predict if reaction is spontaneous at 263KIs it possible to freeze water at 263K ( -10oC)At -10oC Ssys Ssurrounding + S universe 21. Using H and S to predict if reaction is spontaneous at 263KIs it possible to freeze water at 263K ( -10oC)At -10oCSsysSsurrounding + S universeConclusion : Spontaneous - Entropy of system S sys DECREASES BUTheat released to surrounding INCREASES the entropy of surrounding, S surroundingresulting in an INCREASES in total Entropy of the Universe 22. Using H and S to predict if reaction is spontaneous at 298KAt 25oCIs it possible to decompose CaCO3 (s) CaO (s) + CO2 (g)Ssys Ssurrounding+ 23. Using H and S to predict if reaction is spontaneous at 298KAt 25oCIs it possible to decompose CaCO3 (s) CaO (s) + CO2 (g)Ssys Ssurrounding+S universe 24. Using H and S to predict if reaction is spontaneous at 298KAt 25oC Is it possible to decompose CaCO3 (s) CaO (s) + CO2 (g)SsysSsurrounding + S universeConclusion : Non Spontaneous - Entropy of system S sys INCREASES BUTheat absorbed from surrounding DECREASES the entropy of surrounding, S surroundingresulting in a DECREASE in Total Entropy of universe 25. Using H and S to predict if reaction is spontaneous at 1500KAt 1227oC Is it possible to decompose CaCO3 (s) CaO (s) + CO2 (g) Ssys Ssurrounding + 26. Using H and S to predict if reaction is spontaneous at 1500KAt 1227oC Is it possible to decompose CaCO3 (s) CaO (s) + CO2 (g) Ssys Ssurrounding + S universe 27. Using H and S to predict if reaction is spontaneous at 1500KAt 1227oC Is it possible to decompose CaCO3 (s) CaO (s) + CO2 (g) Ssys Ssurrounding + S universeConclusion : Spontaneous - Entropy of system S sys INCREASES more than >DECREASES in entropy of surr, S surr due to heat absorbed from surroundingresulting in a NET INCREASE in Total Entropy of universe 28. Using H and S to predict if reaction is spontaneous at 298KIs it reaction possible 2NO (g) + O2 (g) 2NO2 (g) 29. Using H and S to predict if reaction is spontaneous at 298KIs it reaction possible 2NO (g) + O2 (g) 2NO2 (g)SsysSsurrounding+ 30. Using H and S to predict if reaction is spontaneous at 298KIs it reaction possible 2NO (g) + O2 (g) 2NO2 (g)SsysSsurrounding+ S universe 31. Using H and S to predict if reaction is spontaneous at 298KIs it reaction possible 2NO (g) + O2 (g) 2NO2 (g)SsysSsurrounding+ S universeConclusion : Spontaneous - Entropy of system S sys DECREASES less than