Equilibrium

Condition in which the forward and reverse processes are taking place at the same rate.

Which are at equilibrium ?

Burning Methane	Beaker of Sugar	NO2 and N2O4

Dynamic:
Forward and reverse Rxns both taking place
Rate_forward = Rate_Reverse
No net change in composition

Change T, P, reagent concentrations - entire system re-adjusts.
Composition of mixture changes.

Kinetic statement of equilibrium ...
Thermodynamic statement of equilibrium ...