Kp = pNO²/ pN₂pO₂; (No units) where; pNO is the partial pressure of NO; pN₂ is the partial pressure of nitrogen pO₂ is the partial pressure of Oxygen The equilibrium constant Kp is deduced from the balanced chemical equation for a reversible reaction, NOT experimental data as is the case for rate expressions in kinetics. Kp changes with temperature considerably changing the position of an equilibrium, and, at a constant temperature, and therefore constant K, the position of an equilibrium can change significantly depending on relative concentrations/pressures of 'reactants' and 'products'.
