Chemical Change: Factors Affecting the Position of Equilibrium

Equilibrium refers to the state in a chemical reaction where the concentrations of the reactants and products do not change. Both the forward and the reverse reactions are occurring at the same rate.
Le Chatelier’s principle asserts that if a change is applied to a system at equilibrium, the system will adjust to partially offset the change and re-establish equilibrium. This can be applied to changes in concentration, pressure, and temperature.
If the concentration of a reactant or product in a system at equilibrium is changed, the position of the equilibrium will shift to oppose the change. If a reactant is added, the system will try to use up the extra by making more product, thus shifting the equilibrium to the right. Conversely, if a product is removed, the system will try to produce more of it, shifting the equilibrium to the left.
Pressure only affects equilibrium in reactions involving gases. If the pressure is increased, the equilibrium will shift towards the side with fewer gas molecules to decrease pressure again. Conversely, if the pressure is decreased, the equilibrium will shift towards the side with more gas molecules.
If temperature is increased, the equilibrium will shift in the direction of the endothermic reaction (which absorbs heat) to decrease the temperature. If the temperature is decreased, it will shift in the direction of the exothermic reaction (which releases heat) to increase the temperature.
Catalysts do not affect the position of equilibrium. They increase the rate of both the forward and reverse reactions equally, so the system reaches equilibrium faster, but the concentrations of the reactants and products at equilibrium do not change.
Remember to use Le Chatelier’s principle to predict and explain the shift in the position of equilibrium following a change in conditions, such as concentration, pressure, or temperature.
Understanding this concept is crucial for predicting the outcomes of changes in industrial processes as it allows for predictions about how changes to conditions will impact the yield of products.