Equilibrium Flashcards
What are the characteristics of a system at equilibrium?
- a reversible reaction
- in a closed system
- macroscopic properties do not change
- the concentration of reactants and products at constant but not necessarily the same
What is Le Chatelier’s principle
If a system is at equilibrium and a change is made that upsets the equilibrium, the the system alters in such a way as to counteract the disturbance, and a new equilibrium is established
How does concentration affect equilibrium?
Rate of reaction: higher rate of successful collisions in the correct orientation to overcome the activation energy.
Yield: the equilibrium favors the side with fewer molecules.
How does temperature effect equilibrium?
Rate of reaction: An increase in temperature results in an increase of average kinetic energy. If the particles are moving faster they are increasing the rate of collision. A higher rate of collision provides a greater chance of successful collisions in the correct orientation and as a result there is a higher rate of reaction
Equilibrium: an increase in temperature favors the endothermic reaction and a decrease Favors the exothermic. This is according to LCP which states that at equilibrium a system moves to counteract the disturbances imposed by a change. In this case, if there is an increase in temperature, the endothermic reaction is favored as to absorb this excess in temperature and vice versa for the exothermic reaction.
What is the equilibrium constant affected by?
Increase of Temperature: if the reaction is exothermic then the formation of reactants is favored, decreasing the value of K. An endothermic reaction favors the formation of products increasing the value of K.
What is K unaffected by?
K is not affected by concentration or pressure is this only change the position of the equilibrium. K is not affected by the addition of a catalyst either.
