1. Equilibrium Conceptual Kahyee

2. 1994 A Le Chatelier’s principle If a “chemical system at equilibrium experiences a change in concentration, temperature or total pressure the equilibrium will shift in order to minimize that change.”

3. 1994 A This idea is extremely important when you’re faced with a problem that asks you what will happen when a certain change is made to an equilibrium Basically there are a few basic changes that are applied often to equilibriums in questions 1.A certain reactant or product is added to the equilibrium 2.The temperature changes 3.Change in pressure 4.Change in volume

4. 1994 A When a certain substance is added to an equilibrium the expression will shift the opposite way in order to minimize the change being added to it For instance If you added more A or B the equilibrium would shift to the right, but if you added more C or D the equilibrium would shift to the left which because it wants to reduce the change of adding a substance to it A + BC + D

5. 1994 A When the temperature of an equation is changed you must examine the delta H value If the delta H value is positive then the equation is endothermic, if it is negative then the equation is exothermic An increase in heat will always favor the endothermic side, in other words an increase in heat will shift to the right if the equilibrium is endothermic, and to the left if the equilibrium is exothermic For instance look at the below equilibrium expression Now imagine that it was endothermic, in order for the reaction to occur there needs to be heat added to the left side A + B C + D A + B + heatC + D So it makes sense that the equilibrium will shift towards the endothermic side

6. 1994 A Pressure and Volume are just other changes that can occur to an equilibrium The reaction will try and lesson that change so if the pressure increases it will try and decrease the pressure by shifting towards the side with the least amount gas molecules Volume is inversely proportional to pressure When volume increases, Pressure decreases and vice versa There fore when volume increases the reaction will shift to the side with the most gas molecules in order to regain the pressure that was lost

7. That will get you like a couple really easy multiple choice questions right, and maybe even a portion of the free response if you’re lucky Peace -KFong