Skill 26.4 Apply Le Chateliers principle to analyze reversible reactions

Skill 26.4 Apply Le Chatelier s principle to analyze reversible reactions. 

A system at equilibrium is in a state of balance because forward and reverse processes are taking place at equal rates. If equilibrium is disturbed by changing concentration, pressure, or temperature, the state of balance is upset for a period of time before the equilibrium shifts to achieve a new state of balance. Le Chatelier s principle states that equilibrium will shift to partially offset the impact of an altered condition. 

If a chemical reaction is at equilibrium, Le Chatelier s principle predicts that adding a substance—either a reactant or a product— will shift the reaction so a new equilibrium is established by consuming some of the added substance. Removing a substance will cause the reaction to move in the direction that forms more of that substance. 

Example The reaction Equilibrium is established, and then additional CO is added to the reaction vessel. Predict the impact on each reaction component after CO is added. 

Solution Le Chatelier s principle states that the reaction will shift to partially offset the impact of the added CO. Therefore, CO concentration will decrease, and the reaction will shift to the right. H2 concentration will also decrease and CH3OH concentration will increase. 

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