Kinetics Lesson 4 PE Diagrams Potential Energy Diagrams

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Kinetics Lesson 4 PE Diagrams

Kinetics Lesson 4 PE Diagrams

Potential Energy Diagrams Kinetic Energy (k. J) Heat energy due to the motion of

Potential Energy Diagrams Kinetic Energy (k. J) Heat energy due to the motion of particles. Simulation Potential Energy or Enthalpy (H). Bond Energy (k. J) ΔH means change in enthalpy It is also called the heat of the reaction because it tells you how much heat or KE was produced or consumed by the reaction.

PE + KE = Conservation of Energy PE KE ΔH Total Energy is constant

PE + KE = Conservation of Energy PE KE ΔH Total Energy is constant Reaction Type Decreases Increases -ve exothermic Increases Decreases +ve endothermic When PE (bond energy) decreases it is converted into KE which increases. Remember that KE is heat energy, so it gets hotter and it is exothermic.

Potential Energy Diagrams Exothermic Show the change in potential energy or enthalpy during a

Potential Energy Diagrams Exothermic Show the change in potential energy or enthalpy during a successful collision. On the right Standard Notation: H 2 + I 2 → 2 HI + 170 k. J Or negative ΔH Notation: H 2 + I 2 → 2 HI ΔH = -170 k. J Both notations indicate an exothermic reaction. The first indicates that 170 KJ of KE are produced, while the second shows that the PE decreases by 170 KJ.

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 KJ 1. An H 2 and I 2 approach each other

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 1. Reactants H 2 and I 2 approach each other Reactants PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 2. They collide and become an Activated Complex PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 2. They collide and become an Activated Complex Unstable Reaction Intermediate High PE Low KE Bonds Break & Form Reactant bonds break Activated complex bonds form PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 3. New bonds form and products separate PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 3. New bonds form and products separate activated complex bonds break product bonds form PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 3. New bonds form and products separate Activated Complex Reactants Products PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 3. New bonds form and products separate Ea(for) Ea(rev) PE Reaction Path

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I

Lets Explore the Potential Energy Changes during a Single Collision H 2 + I 2 → 2 HI + 170 k. J 3. New bonds form and products separate Ea PE Ea(rev) ΔH = -ve Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the activation energy is 200 k. J H 2 + I 2 → 2 HI ΔH = -170 k. J PE (KJ) 600 400 200 0 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the activation energy is 200 k. J H 2 + I 2 → 2 HI ΔH = -170 k. J 600 reactants PE 400 (KJ) 200 0 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the activation energy is 200 k. J H 2 + I 2 → 2 HI ΔH = -170 k. J 600 reactants Ea PE 400 (KJ) 200 0 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the activation energy is 200 k. J H 2 + I 2 → 2 HI ΔH = -170 k. J 600 reactants Ea PE 400 (KJ) ΔH 200 0 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the activation energy is 200 k. J. H 2 + I 2 → 2 HI ΔH = -170 k. J 600 PE (KJ) 400 reactants Ea ΔH 200 0 Reaction Path

Potential Energy Diagrams Endothermic Standard Notation: on left or positive I 2 + Cl

Potential Energy Diagrams Endothermic Standard Notation: on left or positive I 2 + Cl 2 + 100 k. J → 2 ICl ΔH Notation: I 2 + Cl 2 → 2 ICl ΔH = + 100 k. J Both notations indicate an endothermic reaction. The first indicates that 100 k. J of KE are consumed, while the second shows that the PE increases by 100 k. J.

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the energy of the activated complex is 600 k. J. I 2 + Cl 2 + 100 KJ → 2 ICl PE 600 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the energy of the activated complex is 600 k. J. I 2 + Cl 2 + 100 KJ → 2 ICl PE 600 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the energy of the activated complex is 600 k. J. I 2 + Cl 2 + 100 KJ → 2 ICl PE 600 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the energy of the activated complex is 600 k. J. I 2 + Cl 2 + 100 KJ → 2 ICl PE 600 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the energy of the activated complex is 600 k. J. I 2 + Cl 2 + 100 KJ → 2 ICl PE 600 ΔH = + 100 KJ 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 k. J

Draw the PE diagram if the enthalpy of the reactants is 400 k. J and the energy of the activated complex is 600 k. J. I 2 + Cl 2 + 100 KJ → 2 ICl PE 600 400 200 ΔH = + 100 KJ Reaction Path

Draw the PE diagram if the enthalpy of the reactants is 400 KJ and

Draw the PE diagram if the enthalpy of the reactants is 400 KJ and the energy of the activated complex is 600 KJ. I 2 + Cl 2 + 100 KJ → 2 ICl Ea PE 600 ΔH = + 100 KJ 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J PE (KJ) 600 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J 600 PE 400 (KJ) 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J PE (KJ) 600 Ea (rev) = 400 k. J 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J PE (KJ) 600 Ea (rev) = 400 k. J 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J 600 Ea (for) = 200 k. J PE Ea (rev) = 400 k. J (KJ) 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J 600 Ea (for) = 200 k. J PE Ea (rev) = 400 k. J (KJ) 400 200 Reaction Path

Draw the PE diagram if the enthalpy of the products is 200 k. J,

Draw the PE diagram if the enthalpy of the products is 200 k. J, the Ea (for) = 200 k. J, and Ea (rev) = 400 k. J 600 Ea (for) = 200 k. J PE Ea (rev) = 400 k. J (KJ) 400 ΔH = -200 k. J 200 Reaction Path

Exothermic Reaction

Exothermic Reaction

Exothermic Reaction Uncatalyzed reaction

Exothermic Reaction Uncatalyzed reaction

Exothermic Reaction Catalyzed reaction Uncatalyzed reaction

Exothermic Reaction Catalyzed reaction Uncatalyzed reaction

Exothermic Reaction Reactants Products

Exothermic Reaction Reactants Products

Exothermic Reaction Reactants Products stronger bonds

Exothermic Reaction Reactants Products stronger bonds

Exothermic Reaction Downhill in PE KE is produced

Exothermic Reaction Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) H Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) H Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) Ea(rev)(cat) H Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) Ea(rev)(cat) H Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) Ea(rev)(uncat) Ea(rev)(cat) H Downhill in PE KE is produced

Exothermic Reaction Ea(for)(uncat) Ea(for)(cat) Ea(rev)(uncat) Ea(rev)(cat) H Downhill in PE KE is produced

PE(k. J) 500 400 300 200 100 0 H forward H reverse Ea forward

PE(k. J) 500 400 300 200 100 0 H forward H reverse Ea forward uncat Ea reverse uncat Ea forward cat reaction path = = =

PE(k. J) 500 400 300 200 100 0 H forward = H reverse =

PE(k. J) 500 400 300 200 100 0 H forward = H reverse = Ea forward uncat = Ea reverse uncat = Ea forward catalyzed = reaction path -300 k. J

PE(k. J) 500 400 300 200 100 0 H forward = H reverse =

PE(k. J) 500 400 300 200 100 0 H forward = H reverse = Ea forward uncat = Ea reverse uncat = Ea forward catalyzed = reaction path -300 k. J +300 k. J

PE(k. J) 500 400 300 200 100 0 H forward = H reverse =

PE(k. J) 500 400 300 200 100 0 H forward = H reverse = Ea forward uncat = Ea reverse uncat = Ea forward catalyzed = reaction path -300 k. J +300 k. J 100 k. J

PE(k. J) 500 400 300 200 100 0 H forward = H reverse =

PE(k. J) 500 400 300 200 100 0 H forward = H reverse = Ea forward uncat = Ea reverse uncat = Ea forward catalyzed = reaction path -300 k. J +300 k. J 100 k. J 400 k. J

PE(k. J) 500 400 300 200 100 0 H forward = H reverse =

PE(k. J) 500 400 300 200 100 0 H forward = H reverse = Ea forward uncat = Ea reverse uncat = Ea forward catalyzed = reaction path -300 k. J +300 k. J 100 k. J 400 k. J 50 k. J

PE(k. J) reaction path Slow rate due to high Ea

PE(k. J) reaction path Slow rate due to high Ea

PE(k. J) reaction path The only way to change the PE diagram is to

PE(k. J) reaction path The only way to change the PE diagram is to add a catalyst.

PE(k. J) reaction path The only way to change the PE diagram is to

PE(k. J) reaction path The only way to change the PE diagram is to add a catalyst. More low energy collisions are successful!

PE(k. J) reaction path Slow rate due to high Ea

PE(k. J) reaction path Slow rate due to high Ea

PE(k. J) 500 400 300 200 100 0 reaction path Increasing the temperature does

PE(k. J) 500 400 300 200 100 0 reaction path Increasing the temperature does not change the diagram. It gives more collisions the required Ea and more are successful. Increasing the concentration, pressure, and surface area does not change the diagram.