[gavin31]

Hi
I just got assigned a new assignment regarding chemical equilibrium and I have no idea what to do.

One of the questions are:
I'm required to explain the effect that the following would do to the equilibrium according to Le Chaterlier's principle and then state which way the equilibrium would shift.

CO2(g) + 1/2 O2(g) <------> CO2(g) + 28.3 kJ
a) increase in temperature
b) increase in [O2]
c) introduce a catalyst
d) increase pressure by adding He(g)

Any help would be great. You can email me at gavinross31@hotmail.com
Thanks in advance!

[Vette Freak]

Did you mean to type CO(g) + 1/2 O2(g) <------> CO2(g) + 28.3 kJ ?

Le Chatelier's Principle states the equilibrium of a reaction will shift in such a way as to reduce/counter the effects of a change.

a) When the temperature increases, the reaction shifts towards the endothermic side to use the excess heat energy.  In this case, the forward reaction is exothermic so it shifts to the left.

b)  To counter an increase in a product or reactant, the reaction shifts in the direction that will use up the compound in excess. It shifts to the right.

c)  Introducing a catalyst will not shift the equilibrium of a reaction because it only increases the rate by decreasing the required activation energy.

d)  An increase in pressure will cause the equilibrium to shift in the direction that reduces the total number of gas molecules so the pressure will decrease.  In this case, there are 1.5 molecules on the left and 1 on the right so it will shift to the right.

[gavin31]

thanks!

and another question, do you know any good sites where it explains the graph for these changes in equilibrium?

[Donaldson Tan]

check out our links section under "Chemistry Websites"