Effect of tripling the pressure on the equilibrium n2o4(g) 2no2(g) is that
Answers
Shifting Equilibria: Le Chatelier’s Principle
Once equilibrium is established, the reaction is over, right? Not exactly. An experimenter has some ability to affect the equilibrium.
Chemical equilibria can be shifted by changing the conditions that the system experiences. We say that we “stress” the equilibrium. When we stress the equilibrium, the chemical reaction is no longer at equilibrium, and the reaction starts to move back toward equilibrium in such a way as to decrease the stress. The formal statement is called Le Chatelier’s principle: If an equilibrium is stressed, then the reaction shifts to reduce the stress.
There are several ways to stress an equilibrium. One way is to add or remove a product or a reactant in a chemical reaction at equilibrium. When additional reactant is added, the equilibrium shifts to reduce this stress: it makes more product. When additional product is added, the equilibrium shifts to reactants to reduce the stress. If reactant or product is removed, the equilibrium shifts to make more reactant or product, respectively, to make up for the loss.
Example 6
Given this reaction at equilibrium:
N2 + 3 H2 ⇄ 2 NH3
In which direction—toward reactants or toward products—does the reaction shift if the equilibrium is stressed by each change?
H2 is added.
NH3 is added.
NH3 is removed.
Solution
If H2 is added, there is now more reactant, so the reaction will shift toward products to reduce the added H2.
If NH3 is added, there is now more product, so the reaction will shift toward reactants to reduce the added NH3.
If NH3 is removed, there is now less product, so the reaction will shift toward products to replace the product removed.