What is the effect of temperature on equilibrium?

Temperature changes can shift the position of equilibrium, either favouring the endothermic or exothermic reaction.

In more detail, the effect of temperature on equilibrium is based on Le Chatelier's Principle, which states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change. In the context of temperature, if the temperature is increased, the equilibrium will shift in the direction of the endothermic reaction to absorb the extra heat. Conversely, if the temperature is decreased, the equilibrium will shift in the direction of the exothermic reaction to release heat and increase the temperature.

For example, consider the equilibrium between nitrogen dioxide (NO2) and dinitrogen tetroxide (N2O4). This is an exothermic reaction in the forward direction, meaning it releases heat. If the temperature is increased, according to Le Chatelier's Principle, the equilibrium will shift to the left to absorb the extra heat, favouring the endothermic reaction and producing more NO2. If the temperature is decreased, the equilibrium will shift to the right, favouring the exothermic reaction and producing more N2O4.

It's also important to note that changing the temperature also changes the value of the equilibrium constant, K. For endothermic reactions, an increase in temperature increases the value of K, meaning the reaction produces more products. For exothermic reactions, an increase in temperature decreases the value of K, meaning the reaction produces more reactants.

In summary, temperature plays a crucial role in determining the position of equilibrium and the concentrations of reactants and products in a chemical reaction. Understanding this concept is key to manipulating chemical reactions in various scientific and industrial applications.