Dynamic Equilibrium & Le Chatelier's Principle

Reversible Reaction

A reaction where products can react to reform the original reactants; represented with a double arrow

Dynamic Equilibrium

State in a closed system when the rate of the forward reaction equals the rate of the reverse reaction; concentrations remain constant

Closed System

Required for dynamic equilibrium; no substances can enter or leave

Le Chatelier’s Principle

If a system at equilibrium is disturbed, it will shift to counteract the change

Effect of Temperature

Increase temperature → equilibrium shifts to endothermic side; decrease temperature → equilibrium shifts to exothermic side

Effect of Pressure

Increase pressure → equilibrium shifts to side with fewer moles of gas; decrease pressure → shifts to side with more moles of gas

Effect of Concentration

Increase reactant concentration → forward reaction favoured; decrease reactant concentration → backward reaction favoured

Catalysts

Increase rate of forward and reverse reactions equally; do not change equilibrium position

Rate vs Yield

Altering conditions can increase product yield but may decrease rate; industrial conditions balance yield, rate, safety, and economics

Industrial Consideration

Compromise conditions are used to achieve reasonable yield and rate while maintaining safety and cost-effectiveness