Chemical Equilibrium — A/L Chemistry

Dynamic chemical equilibrium is achieved in a closed system when forward and backward reaction rates are equal, keeping macroscopic concentrations and properties constant over time.

Check before you answer

1. State Symbols & Expression: Strict inclusion of state symbols (g, aq) and explicit exclusion of pure solids (s) and pure liquids (l) from Kc and Kp expressions.
2. Le Chatelier vs Equilibrium Constant: Explicit distinction between temperature (which alters the numerical value of Kc/Kp) versus concentration or pressure changes (which shift the reaction quotient Q without altering K).
3. Derived Units: Correct deduction of stoichiometric units for Kc/Kp (e.g., mol dm⁻³, kPa) or explicitly stating 'dimensionless' when Δn = 0.