Shifting Equilibrium - The Big Three Factors
Want to control where your equilibrium sits? You've got three powerful tools: concentration, temperature, and pressure. Mastering these will make you unstoppable in equilibrium problems.
Concentration changes are straightforward. Add more reactant or remove product? The equilibrium shifts right to make more product. Add product or remove reactant? It shifts left. Think of it as the reaction trying to undo whatever you just did.
Temperature effects depend on whether your reaction is endothermic or exothermic. For endothermic reactions, increasing temperature shifts right (more product), whilst decreasing temperature shifts left. Exothermic reactions behave oppositely - higher temperature shifts left, lower temperature shifts right.
Pressure changes only matter when you have different numbers of gas molecules on each side. Increase pressure? The equilibrium shifts towards whichever side has fewer molecules. Decrease pressure? It shifts towards the side with more molecules.
Exam Tip: Remember that equilibrium always tries to counteract whatever change you make to the system - this is Le Chatelier's principle in action.