# Equilibria

Le Châtelier's Principle: If stress is applied to a system at equilibrium, the equilibrium will shift in such a way as to relieve the stress. e.g. if the pressure of carbon dioxide is increased over a solution of carbon dioxide in water, more carbon dioxide will dissolve, reducing the pressure increase.

Consider the reaction

CO + NO2 NO + CO2 + heat (226 kJ)

Note that heat appears on the product side - the system is giving up heat, \ DH is negative, DH = - 226 kJ

So, what will happen to [CO2] if:

• press 1 for [CO2] increases
• press 2 for [CO2] decreases
• press 3 for no change in [CO2]

CO + NO2 NO + CO2 + heat (226 kJ)

So, what will happen to [CO2] if:

• press 1 for [CO2] increases
• press 2 for [CO2] decreases
• press 3 for no change in [CO2]

CO + NO2 NO + CO2 + heat (226 kJ)

So, what will happen to [CO2] if:

• press 1 for [CO2] increases
• press 2 for [CO2] decreases
• press 3 for no change in [CO2]

CO + NO2 NO + CO2 + heat (226 kJ)

So, what will happen to [CO2] if:

• T is increased?
• press 1 for [CO2] increases
• press 2 for [CO2] decreases
• press 3 for no change in [CO2]

CO + NO2 NO + CO2 + heat (226 kJ)

So, what will happen to [CO2] if

• V is increased?
• press 1 for [CO2] increases
• press 2 for [CO2] decreases
• press 3 for no change in [CO2]

CO + NO2 NO + CO2 + heat (226 kJ)

So, what will happen to [CO2] if