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:

    • CO is added?
          • 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:

    • NO2 is added?
          • 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:

    • NO is added?
          • 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

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

 

© R A Paselk

Last modified 4 December 2008