A system in which mass is conserved inside the system but energy can enter or leave the system freely.
An open system
A system in which both energy and matter can be exchanged between the system and its surroundings
Le Châtelier’s principle
when an external stress (change in pressure,temperature or concentratio) is applied to a system in dynamicchemical equilibrium, the equilibrium point will change in such a way as to counteract the stress.
