Chemical equilibrium comprehensive notes

CHEMICAL EQUILIBRIUM

Open System
 Continuously interacts with its environment

Closed System
 Isolated from its surroundings
 No reactants or products can leave or enter the system

Reversible Reaction
 A reaction in which products can be converted back to reactants
 Represented by ⇄ (in equilibrium: ⇌)


Dynamic Equilibrium
 Chemical equilibrium is a dynamic equilibrium when the rate of the
forward reaction equals the rate of the reverse reaction

Le Chatelier’s Principle

 When the equilibrium in a closed system is disturbed, the system
will re-instate a new equilibrium by favouring the reaction that will
oppose the disturbance

Favouring a Reaction
 If the forward reaction is favoured:
1. Rate of the forward reaction > Rate of the reverse reaction
2. Equilibrium position will shift right
 If the reverse reactions is favoured
1. Rate of the forward reaction < Rate of the reverse reaction
2. Equilibrium position will shift left
 The reaction that counteracts the disturbance in equilibrium will be
favoured

Factors affecting Equilibrium Position

Concentration
 Equilibrium will shift to decrease any increase in concentration of
either reactants or products:
1. Adding Reactantforward reaction favoured
2. Adding Productreverse reaction favoured
 Equilibrium will shift to increase any decrease in concentration of
either reactants or products:
1. Removing Reactantreverse reaction favoured