dynamic equilbria Flashcards
(33 cards)
what are the conditions needed for a reversible reaction
-forward and backward reactions happen at equal rates
-reactants and products have a constant concentration
-the reaction occurs in a closed system so none of the products or reactants can escape
give an example of a reversible reaction
-the forwards reaction is ending
-hydrated copper sulfate is blue because it reflects blue light and absorbs other light
-the crystal has absorbed some of the water so water is trapped inside the giant ionic lattice
many reversible reactions in a closed state can reach what?…
dynamic equilibrium
what is a closed system
nothing can get in or out
What happens at dynamic equilibrium
both reactions are taking place:
simultaneously, and at the same rate, in a closed system, conc. of products and reactants remain constant(not equal)
What is Le Chatelier’s Principle
If the conditions of a system are changed, the position of the equilibrium moves to oppose that change
Le Chateliers Principle:
If you want increase the temperature of any reaction
what happens?
reaction shifts to endothermic
Le Chateliers Principle:
If you want increase the pressure of any reaction
what happens?
Reaction shifts to the side where there is the least amount of moles
Negative enthalpy change=
exothermic reaction
What is le chateliers principle explanation for the increase in temperature if the forward reaction is exothermic
If T is increased, equilibrium position moved to oppose increase in T by moving left in endothermic direction which decreased equilibrium yield of x
more gas particles=
more pressure
What is le chateliers principle explanation for the increase in pressure if the forward reaction has fewer molecules
If P is increased
equilibrium moves to oppose increase in P by moving right to side with fewer gas molecules which increases equilibrium yield of x
What happens if pressure is increased or decreased in a reaction where there’s the same number of molecules in the forward and backward reactions
no effect
What is le chateliers principle explanation for the increase in concentration of the reactants
Equilibrium position moves to oppose increase of x by moving to the right to us it up which increases the equilibrium yield of y
What are the conditions for the haber process
What are the conditions needed for the contact process
What do need to consider when coming up with the conditions needed for the haber process
-cost: If temp or pressure is high, it will be expensive but the rate of reaction will also be high. We need to find a compromise
-rate of reaction
-if the forward reaction is exothermic or endothermic
In the dynamic equilibria graph, when has equilibrium been reached
What is the equilibrium constant, Kc, defined as?
If Kc>1 what does that mean?
equilibrium shifts to the right(higher yield)
If Kc<1, what does that mean?
the equilibrium shifts to the left(lower yield)
If you change the concentration of something present in the mixture at equilibrium what happens to equilibrium constants?
Equilibrium constants do not change
What is the only thing that changes an equilibrium constant?
a charge of temperature
