1.Video Tutorial on Energetics, Enthalpychanges, Exothermic and Endothermicreactions. Prepared by Lawrence Kok http://lawrencekok.blogspot.com

2. Video on Energetics and Enthalpy Changes Video on endo and exo Video on ammonium salt , endo and exo reaction reactionVideo on difference between Temp vs HeatDetail lecture on Energetics 3. Energetics ( Enthalpy Change )Enthalpy Heat content of a system stored as chemical energy in chemical bondsBond Making Heat energy given off/releasedBond Breaking Heat energy taken in /absorbed During bond making + bond breaking certain amount energy is either ABSORBED or RELEASED 4. Energetics ( Enthalpy Change ) Enthalpy Changes 5. Energetics ( Enthalpy Change ) Enthalpy Changes 6. Basic Rules for H Enthalpy changes calculations1 Total amt energy released/absorbed is to number of moles of reactants2 H for reverse reaction is EQUAL in magnitude but opposite in sign to H forward3 Standard condition for measuring STANDARD ENTHALPY CHANGE, H4 Unit for H is KJ mol -1 7. Basic Rules for H Enthalpy changes calculationsTemp and Heat56 Enthalpy change H measured using a calorimeter7Specific heat capacity for a substance water ( 4.18J g-1K-1) 8. Enthalpy Change for Displacement Rxn,H (displacement ) 9. Enthalpy Change for Displacement Reaction, H H Heat of Displacement is heat released when ONE mole metal displaced from salt solution by a more reactive/electropositive metal. H Enthalpy Method/ProcedureDisplacement Reaction Change Displacement rxn DiagramCalculationEnergy Level Diagram 10. Enthalpy Change for Displacement Reaction, HH Heat of Displacement is heat released when ONE mole metal displacedfrom salt solution by a more reactive/electropositive metal.H Enthalpy Change Displacement rxnAssumptions /Sources of errorsImprovements 11. Enthalpy Change for Displacement Reaction, H Calculation of H DisplacementMore reactive metal displaces less reactive metal from its solutionEx 1 : Excess Al added to 100ml, 0.1M FeSO4, 0.48g Fe produced and Temp changes from 28C to 33.5CCalculate Enthalpy of displacement 12. Enthalpy Change for Displacement Reaction, H Calculation of H DisplacementMore reactive metal displaces less reactive metal from its solutionEx 1 : Excess Al added to 100ml, 0.1M FeSO4, 0.48g Fe produced and Temp changes from 28C to 33.5CCalculate Enthalpy of displacement 13. Enthalpy Change for Displacement Reaction, H Calculation of H DisplacementMore reactive metal displaces less reactive metal from its solutionEx 2 : 0.7g of Fe added to 50ml, 0.5M CuCl2 solution. Initial Temp = 30C. Calculate the final tempusing Energy Level Diagram given on the right 14. Enthalpy Change for Combustion reactionH (combustion) 15. Enthalpy Change for Combustion reaction, HH Heat of Combustion is heat released when ONE mole substance burnt completely in excess oxygen Combustion Reaction H EnthalpyMethod/Procedure Change Combustion rxn Diagram Calculation Energy Level Diagram 16. Enthalpy Change for Combustion reaction, HH Heat of Combustion is heat released when ONE mole substance burnt completely in excess oxygen H Enthalpy Change Combustion rxnAssumptions /Sources of errors/Improvements Combustion data for various alcohols 17. Enthalpy Change for Precipitation reaction H (precipitation ) 18. Enthalpy Change for Precipitation reaction, HH Heat of precipitation is heat released when ONE mole of precipitate is formed from its solution. Precipitation Reaction H Enthalpy Method/ProcedureChange precipitation rxnCalculation Diagram Energy Level Diagram 19. Enthalpy Change for precipitation reaction, HH Heat of precipitation is heat released when ONE mole of precipitate is formed from its solution.H EnthalpyChange precipitation rxn Sources of errors/ImprovementsResults 20. Enthalpy Change for Neutralization reaction H (neutralization ) 21. Enthalpy Change for Neutralization between Strong Acid and Strong BaseH Heat of neutralization is heat released when ONE mole of water is formed from 1 mol H+ + 1 mol OH-. Neutralization Reaction H EnthalpyMethod/ProcedureChange Neutralization rxn CalculationDiagramEnergy Level Diagram Strong acid and Strong base 22. Enthalpy Change for Neutralization between Weak Acid and Strong BaseH Heat of neutralization is heat released when ONE mole of water is formed from 1 mol H+ + 1 mol OH-. Neutralization Reaction H EnthalpyMethod/ProcedureChange Neutralization rxn CalculationDiagramEnergy Level Diagram Weak acid and Strong base 23. Enthalpy Change for Neutralization between Strong Acid and Strong BaseEnthalpy Change for Neutralization between Weak Acid and Strong Base Strong Acid and Weak Base H neutralization is always less than -57.3kJ mol-1Some energy released from the neutralization reaction is ABSORBED by system to dissociateweak acid (CH3COOH) or weak base (NH4OH) molecules into ions CH3COOH --------- CH3COO- + H+ NH4OH ------------ NH4+ + OH- 24. Enthalpy Calculation of H Neutralization ReactionEx 1 100ml, 1.2M HCI added to 100ml, 1.2M NH3 and temp rises from 30C to 37.5C Calculate enthalpy of neutralization. 25. Enthalpy Calculation of H Neutralization ReactionEx 1 100ml, 1.2M HCI added to 100ml, 1.2M NH3 and temp rises from 30C to 37.5C Calculate enthalpy of neutralization. Ans 26. Ex 2Ex 3 27. Ex 2AnsEx 3Ans 28. Ex 3 50 ml, 1M HNO3 added to 50ml, 1M KOH. Temp increase by 6.4oC. What will temp change. When 25ml of each solution are mixed together. A. 1.6oC B. 3.2oC C. 6.4oC D. 2.8oCEx 4 H neutralization between HCI and NaOH is -57kJmol-1. Calculate H when 2 mol of H2SO4 reacts with excess KOH A. (-1/2 x 57) kJ B. -57kJ C. (-2 x 57 )kJ D. ( -4 x 57 )kJ 29. Ex 3 50 ml, 1M HNO3 added to 50ml, 1M KOH. Temp increase by 6.4oC. What will temp change. When 25ml of each solution are mixed together. A. 1.6oC B. 3.2oC C. 6.4oC D. 2.8oCAns Ans : If neutralization does not involve change in Conc of acid and base C. 6.4oC (Temp change will be the SAME)Ex 4 H neutralization between HCI and NaOH is -57kJmol-1. Calculate H when 2 mol of H2SO4 reacts with excess KOH A. (-1/2 x 57) kJ B. -57kJ C. (-2 x 57 )kJ D. ( -4 x 57 )kJAns 30. Video on Energetics and Enthalpy Changes Video on endo and exo Video on ammonium salt , endo and exo reaction reactionVideo on difference between Temp vs HeatDetail lecture on Energetics 31. AcknowledgementsThanks to source of pictures and video used in this presentationThanks to Creative Commons for excellent contribution on licenseshttp://creativecommons.org/licenses/Prepared by Lawrence KokCheck out more video tutorials from my site and hope you enjoy this tutorialhttp://lawrencekok.blogspot.com