The equilibrium which exists in a
closed system when the rate of the
forward reaction is equal to the rate of
the reverse reaction
A chemical system is in dynamic equilibrium when:
The concentrations of the
reactants and the products
remain the same
The rate of the forward
reaction is equal to that of the
reverse reaction
The effect of pressure on equilibrium
Changing the pressure only changes the
position of equilibrium if there are gases
present
Increasing the pressure will
shift the position of
equilibrium to the side with
the fewer gas molecules
Decreasing the pressure will shift
the position of the equilibrium to the
side with a greater number of gas
molecules
The effect of temperature on equilibrium
Increasing the temperature shifts the
position of the equilibrium in the
endothermic direction in order to minimise
the temperature increase and absorb energy
Decreasing the temperature shifts the
position of the equilibrium in the
exothermic direction in order to
minimise the temperature decrease and
replace heat energy
Le Chatelier's principle states:
When a system in dynamic equilibrium is
subjected to change the position of the
equilibrium will shift to minimise the
change