chemical+equilibrium


 * Chemical equilibrium** is reached when a chemical reaction stabilizes so that the rate of formation of products is equal to the rate of their reverse reaction.

When following the progress of a reaction, you can picture the following conditions:



As the reaction proceeds, the reactants (A) get consumed, and the products (B) are created. At some point, the products degrade back to their reactant form at the same rate as they are being formed, reaching an equilibrium between formation and destruction. This occurs after about 80 seconds in the above example.

Some chemical reactions go to completion, meaning there is no reverse reaction occurring, and hence no equilibrium. The combustion of a fuel, or the dissociation of a strong acid in water, are examples of completion reactions.

But a large number of chemical reactions stabilize into an equilibrium state, and will vary as to the amounts of reactants and products that are formed.

The extent of a reaction at equilibrium is measured using an **//equilibrium constant//**.