Responding to a change
Le Chatelier’s principle states that when a condition affecting a system at dynamic equilibrium is changed, the position of equilibrium moves in the direction that opposes the effect of that change.
It can be used to predict the effect of changing:
- the concentration of a reactant or product;
- the pressure, where gases are involved;
- the temperature.
A shift in equilibrium changes the relative amounts of reactants and products in the new equilibrium mixture.
| Shift | Result |
|---|---|
| Towards the right | More products are formed and reactants are used. |
| Towards the left | More reactants are formed and products are used. |
Exam Tip: When explaining an equilibrium shift, identify the change first, state which direction opposes it, and then state whether the equilibrium shifts left or right and how the yield changes.