This is the equation
PCl3 + Cl2 = PCl5
In the reaction below:
Increasing the concentration of Cl2 will _____ at equilibrium.
HAVE NO EFFECT
2 answers
You need to review Le Chatelier's Principle. I think the definition given in text books is so esoteric and it really sounds good to me. However, I find that most students don't understand it. I don't know why but here is my definition. Not nearly so esoteric but students usually get it. Ready?
Le Chatelier's Principle says this. When we do something to a chemical system in equilibrium, the reaction will try to undo what we did. Got that? How does that apply to this equation?
PCl3 + Cl2 ==> PCl5
So here is a system at equilibrium. We add more Cl2, the reaction tries to undo what we did. How can it do that you say. It can move the reaction to the right to form more PCl5 because that way will use up at least some of the Cl2 we added. PCl5 will increase, PCl3 will decrease and Cl2 will decrease from the total that's there now (the original + what we added extra) although it can't get rid of ALL of the extra Cl2 we added. This argument works for adding or taking away heat, adding concns of products or reactants. For gaseous reactions, pressure is involved and for that one you just remember that increasing P will shift the equilibrium to the side with the fewer moles.
Le Chatelier's Principle says this. When we do something to a chemical system in equilibrium, the reaction will try to undo what we did. Got that? How does that apply to this equation?
PCl3 + Cl2 ==> PCl5
So here is a system at equilibrium. We add more Cl2, the reaction tries to undo what we did. How can it do that you say. It can move the reaction to the right to form more PCl5 because that way will use up at least some of the Cl2 we added. PCl5 will increase, PCl3 will decrease and Cl2 will decrease from the total that's there now (the original + what we added extra) although it can't get rid of ALL of the extra Cl2 we added. This argument works for adding or taking away heat, adding concns of products or reactants. For gaseous reactions, pressure is involved and for that one you just remember that increasing P will shift the equilibrium to the side with the fewer moles.
4 answers