Equilibrium

  • The word equilibrium implies a state of balance. In an equilibrium state there are no unbalanced potentials (or driving forces) within the system. A system in equilibrium experiences no changes when it is isolated from its surroundings. Thermodynamics deals with equilibrium states.
  • There are many types of equilibrium, and a system is not in thermodynamic equilibrium unless the conditions of all the relevant types of equilibrium are satisfied.
–a system is in thermal equilibrium if the temperature is the same throughout the entire system
–Mechanical equilibrium is related to pressure, and a system is in mechanical equilibrium if there is no change in pressure at any point of the system with time.
–If a system involves two phases, it is in phase equilibrium when the mass of each phase reaches an equilibrium level and stays there.
a system is in chemical equilibrium if its chemical composition does not change with time, that is, no chemical reactions occur.