2. the reaction has to take place in a closed system i.e. a rigid closed
chemical reactions are reversible
BUT
the reaction has to take place
in a closed system i.e. a rigid closed
container with stable external conditions…
temperature, pressure, nothing let in or out!

3. Closed systems reach a state of equilibrium when the RATE of the forward rxn equals the RATE of the reverse rxn
NOTE: It is NOT necessary to have equal amounts of reactants and products

4. Equilibrium is dynamic
When equilibrium is reached the forward and the reverse reactions keep going
BUT
it looks as if the reaction has stopped, because the opposing rates are equal, and the concentrations stay constant!

5. Chemical Tug of War

6. 3 Types of Equilibrium Systems
Chemical reactions (the focus of the rest of this topic)
Solution equilibrium in saturated solutions
at constant temp, the rate of dissolving is equal to the rate of crystallization (precipitation)

7. 3. Physical changes in phases / states
H2O (s) H2O (l)
H2O (l) H2O (g)

9. THE ↔ END