Summary:
- Chemical equilibrium is the state of a system in which the rates of the forward reaction is equal to the rate of the reverse reaction.
- equilibrium can be attained whether the reaction begins with all reactants and no products, all products and no reactants, or some of both.
- At equilibrium, concentrations of all substances are constant.
- The position of equilibrium is a property of the particular reversible reaction and does not depend upon how equilibrium was achieved.
- A system must be closed, meaning no substances can enter or leave the system.