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ENTHALPY. Activation energy, the activated complex, and the effect of a catalyst. Learning Objectives. The activated complex is an unstable arrangement of atoms formed at the maximum of the potential energy barrier, during a reaction.
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ENTHALPY Activation energy, the activated complex, and the effect of a catalyst
Learning Objectives • The activated complex is an unstable arrangement of atoms formed at the maximum of the potential energy barrier, during a reaction. • The activation energy is the energy required by colliding molecules to form an activated complex. • The activation energy can be calculated from potential energy diagrams. • The effect of a catalyst can be explained in terms of alternative reaction pathways with lower activation energy. • A potential energy diagram can be used to show the effect of a catalyst on activation energy.
Energy Reactants Products Reaction Progress
Energy EA Reactants DH Products Reaction Progress
Energy Reactants DH Products Reaction Progress
Energy Reactants DH Products Reaction Progress
Energy EA Reactants DH Products Reaction Progress
What happens here? Energy EA Reactants DH Products Reaction Progress
Reactant A Reactant B
Product C Product C
Activated Complex Energy EA Reactants A + B DH Product C Reaction Progress
NUMBER OF MOLECUES WITH A PARTICULARENERGY Ea MOLECULAR ENERGY
NUMBER OF MOLECUES WITH A PARTICULARENERGY EXTRA MOLECULES WITH SUFFICIENT ENERGY TO OVERCOME THE ENERGY BARRIER Ea MOLECULAR ENERGY
Effect of catalyst Without catalyst Energy EA Reactants DH Products Reaction Progress
Effect of catalyst Energy With catalyst Reactants DH Products Reaction Progress
Effect of catalyst Energy EA With catalyst Reactants DH Products Reaction Progress
Effect of catalyst Without catalyst Energy EA Reactants DH Products Reaction Progress
Effect of catalyst Energy EA With catalyst Reactants DH Products Reaction Progress
Effect of catalyst Without catalyst Energy EA EA With catalyst Reactants DH Products Reaction Progress
