1. Chemical Systems and Equilibrium
simulation?
organic photochromic molecules respond to the UV light

2. Learning Goals:
Explain the concept of dynamic equilibrium, using examples of physical and chemical equilibrium systems.
Explain the concept of chemical equilibrium and how it applies to the concentration of reactants and products in a chemical reaction at equilibrium.

3. Create and complete an ICE table for an equilibrium system.
Draw graphs of c vs. t to illustrate a chemical system approaching equilibrium.
Use appropriate terminology such as dynamic equilibrium, reversible reaction, closed system, equilibrium concentrations, phase equilibrium, solubility equilibrium, chemical equilibrium, equilibrium position
blue bottle
glucose reduces the methylene blue to a colourless form
the oxygen from the air oxidized the colourless form back to the blue
the unused glucose with then reduce the methylene blue to colourless

4. How do the following images represent dynamic equilibrium?
rate of forward reaction = rate of reverse reaction
an observable macroscopic property remains constant
How do the following images represent dynamic equilibrium?
summer haze
Dynamic Equilibrium?
two kids balanced on a teeter-totter
player substitutions during a hockey game
outdoor pool
indoor pool
your own idea?
reaction is reversible p. 420 Fig 1 Blue Bottle McGraw Hill model activity
forward rate = reverse rate
closed system
observable macroscopic property remains constant

5. Consider the following…
Over time, what happens to an open beaker of water?
Over time, what happens to the water level if we cover the beaker?
Water molecules build up and reach a high enough vapour pressure and return to liquid phase, set up an equilibrium, no macroscopic changes but a lot is happening on a molecular level, constant coming and going
We can study equilibrium under closed systems!
Write an equation to describe the equilibrium system.

6. What conditions are required for a dynamic equilibrium to exist?
reaction is reversible
closed system
What are the key characteristics of a dynamic equilibrium?
forward rate = reverse rate
observable macroscopic property remains constant

7. 3 types of Equilibrium Solubility Equilibrium Phase Equilibrium
Chemical Equilibrium
NaCl(s) Na+ (aq) + Cl- (aq)

8. Chemical Equilibrium
Write an equation to describe this equilibrium system.
Initially, N2O4(g) is in the flask. Draw a graph to illustrate the changes in concentration of R and P as the system approaches equilibrium.

9. Does slope = 0 mean the reaction has stopped?
Are the concentrations of R and P equal at equilibrium?