We can use our knowledge of Le Chateliers Principle to make predictions.
Take for example the system at equilibrium below.
We need to predict the effect of imposing changes to the system as shown in the table below.
A good approach is first to determine the effect of the change on the
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower first then the other aspects.
Imposed Change Initial Change to the Forward Reaction Rate Initial Change to the Backward Reaction Rate Final Change to [NO] Final Change to [Br 2] Final Change to [NOBr] New Equilibrium Position Remove some NO Effect is a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower Effect is a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower Shifts to the a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower Remove some NOBr a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower Shifts to the a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower Decreasing the volume of the system a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower Shifts to the a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower
In the first imposed change above when some NO is removed the system counteracts the change by
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower NO to
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower the equilibrium.
So the equilibrium shifts to the
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower . We would of course expect the equilibrium to shift to the
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower if we add some NO. The system will counteract the addition of NO by
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower it from the system.
Due to the sudden removal of NO from the system the forward reaction rate initially will
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower or
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower because now you have
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower of it to react. The initial backwards reaction rate will
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower because its concentration was
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower affected.
When eventually the system has reestablished equilibrium the concentration of bromine will definitely have
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower because more NOBr has
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower to give BR2 and NO. However although NO is produced to counteract the earlier removal, the concentration of NO
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower than when it originally was. It
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower so we consider that as
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower .
Decreasing the volume of a system usually happens when there is an
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower . Hence the equilibrium will definitely
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower to counteract this increase in pressure because overall there will be
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower in the system so the pressure will
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower .
Because of increase in pressure there is
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower for the particles to move about so collision will be
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower . The forward and backward reaction rate will be
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower often so they will both
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower .
Due to an increase in pressure the total no. of particles in the system
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower so we might think that the concentration of NO, Br2 and NOBr
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower . However because the
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower molecules now occupy
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower the concentration actually
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower and
a decrease broken down decrease drop equilibrium position fewer Increase increase in pressure increased left left or <= less less no of molecules less space more more often NIL no effect not at all not change not decrease producing reducing regain right right or => shift to the right will be lower will drop will not be higher would be lower as we would expect.