Concentration affects equilibrium according to Le Chatelier’s Principle: if the concentration of reactants or products is changed, the system will shift to counteract that change and restore equilibrium.
Key points:
- Increasing reactant concentration:
- The system shifts toward products (forward reaction) to consume the extra reactants.
- Decreasing reactant concentration:
- The system shifts toward reactants (reverse reaction) to replace the lost reactants.
- Increasing product concentration:
- The system shifts toward reactants (reverse reaction) to reduce the extra products.
- Decreasing product concentration:
- The system shifts toward products (forward reaction) to replace the missing products.
Summary:
- The system adjusts the reaction direction to partially counteract the concentration change, keeping the equilibrium constant (K) unchanged.
Think of it like a balance scale: adding weight to one side makes the system tip to restore balance.