Equilibrium refers to a state in which there is a balance between opposing forces or processes. In the context of science, it often refers to the state of a system where the rates of forward and reverse reactions are equal.
To solve equilibrium problems, you first need to write out the balanced chemical equation for the reaction. Then, set up an equilibrium expression using the concentration (or partial pressures) of the reactants and products. Finally, use the given information and the equilibrium expression to solve for the unknown variables.
An example of a two equilibrium problem would be the reaction of nitrogen gas (N2) and hydrogen gas (H2) to form ammonia (NH3). The first equilibrium is the formation of nitrogen monoxide (NO) from N2 and oxygen (O2). The second equilibrium is the reaction of NO with H2 to form NH3.
In static equilibrium, there is no net change in the system as the forward and reverse reactions occur at the same rate. In dynamic equilibrium, there is still no net change, but the forward and reverse reactions are still occurring and the concentrations of reactants and products may change over time.
A reaction has reached equilibrium when the concentrations (or partial pressures) of the reactants and products remain constant over time. In other words, the system is no longer changing and the forward and reverse reactions are occurring at the same rate.
