efnajöfnun

Efnajöfnun, meaning "chemical equilibrium" in Icelandic, refers to a state in a reversible chemical reaction where the rates of the forward and reverse reactions are equal. This does not mean that the reaction has stopped; rather, the net concentrations of reactants and products remain constant over time. At equilibrium, the system is dynamic, with molecules continuously converting between reactants and products.

The position of equilibrium describes the relative amounts of reactants and products present when equilibrium is reached. It can be quantified by the equilibrium constant, K. A large K indicates that the equilibrium lies to the right, favoring the formation of products, while a small K indicates that the equilibrium lies to the left, favoring the reactants.

Le Chatelier's principle states that if a change of condition is applied to a system in equilibrium, the system will shift in a direction that relieves the stress. This stress can be a change in concentration, temperature, or pressure. For example, increasing the concentration of a reactant will cause the equilibrium to shift towards the products to consume the added reactant. Similarly, an increase in temperature will favor the endothermic reaction, while a decrease in temperature will favor the exothermic reaction. Changes in pressure primarily affect reactions involving gases.

Understanding chemical equilibrium is crucial in many areas of chemistry, including industrial processes like the Haber-Bosch process for ammonia synthesis, and in biological systems such as enzyme-catalyzed reactions.