equilibria Flashcards
(11 cards)
What does dynamic equilibrium mean?
In a reversible reaction the forwards and backwards reactions occur simultaneously and at the same rate.
What are the features of a system in a state of dynamic equilibrium?
The forwards and backwards reactions occur simultaneously.
The forwards and backwards reactions occur at the same rate.
All reactants and products are present.
Concentrations remain constant.
What is the difference between a homogeneous and a heterogeneous equilibrium?
In a homogeneous equilibrium all reactant/products are in the same state whereas in a heterogeneous equilibrium the reactants/products are in different states.
What is Le Chatelier’s principle?
If the conditions of a reaction at equilibrium are changed, then the position of the equilibrium moves to oppose that change.
What would happen to the equilibrium position if the temperature is increased?
The equilibrium position would shift right/left to favour the endothermic reaction (forwards/backwards reaction) to oppose the increase in temperature.
What would happen to the equilibrium position if the pressure is increased?
The equilibrium position would shift right/left to favour the side with the fewest gas moles (forwards/backwards reaction) to oppose the increase in pressure.
What would happen to the equilibrium position if the concentration is increased?
The equilibrium position would shift right/left to favour the forwards/backwards reaction in order to oppose/ get rid of the increase in concentration.
What would happen to the equilibrium position if a catalyst is used?
A catalyst increases the rate of both the forwards and backwards reactions equally. It does not change the position of the equilibrium, but it reaches equilibrium faster.
How is Kc calculated?
The concentration of products/the concentration of reactant.
How to write a Kc expression?
Kc=[products]/[reactants]
What has an effect on the Kc value?
The Kc value is only affected by temperature. Nothing else effects it.
