Chemical Equilibrium & Le Chatelier's Principle

Dynamic balance between forward and reverse reactions

Chemical equilibrium is a dynamic state where the forward and reverse reaction rates are equal, so concentrations remain constant (but not necessarily equal). The equilibrium constant Kc is calculated from equilibrium concentrations: Kc = [products]^m / [reactants]^n. Large K (>1) favors products; small K (<1) favors reactants. Le Chatelier's Principle: if a system at equilibrium is disturbed, it shifts to partially counteract the disturbance. Adding a reactant → shifts right (more products). Removing a product → shifts right. Increasing pressure (for gases) → shifts toward fewer moles of gas. Increasing temperature → shifts in the endothermic direction (changes K). Catalysts do NOT change the equilibrium position — only reach it faster.