Unit 5: Equilibrium

• Can an argument be made that life is a result of complex set of chemical reactions?
• How does our body know how/when to grow? (e.g. what is homeostasis?)

1. All systems strive for equilibrium, a state in which there is no net change.
2. Reactions occur when molecules collide with enough energy and in the right orientation so the more likely a collision, the more likely a reaction will take place.

IB Objectives: SL      HL

• Equilibrium
  • Classify reactions as reversible or irreversible and recognize that some never go to completion
  • Give an example of dynamic equilibrium
  • State that equilibria take a finite time to be achieved
  • Use LeChâtelier's Principle to predict the effect of a change in the number of moles, volume, or temperature upon the position of an equilibrium
  • Use Le Chatelier's principle to recommend methods to increase the yield of a reaction
  • State and explain the effect of a catalyst on an equilibrium reaction
  • State that equilibrium is reached when the rate of the forward reaction equals the rate of the reverse reaction
  • Describe and explain the application of equilibrium and kinetics concepts to the Haber process and the Contact process
• Math
  • Write equilibrium constants (Keq and Kc) for a chemical reaction
  • Predict the extent of the reaction from magnitude of Kc
  • Calculate values for Keq from final concentrations

• Equilibrium
• Phase Equilibria (HL only)

• Le Chatelier
• Solving Equilibrium Problems

• LeChatelier Lab
• Vapor Pressure (HL only)
• Freezing Point Depression Lab

Animations
• Hydronium Ion Formation
• Hydronium Ion Formation 2
• Acid Dissociation
• Base Formation
• Le Chatelier Flash Animation
• Equilibrium Tutorials