3-Equilibria Flashcards
What is a static equilibrium?
All the processes which might disturb the reaction have stopped
What is a dynamic equilibrium?
The forward and reverse reactions are occurring at the same rate, represented using the double arrow
What is Kc for the reaction:
aA + bB –> cC + dD
[C]^c [D]^d / [A]^a [B]^b
What is Kc?
Equilibrium constant
How would you work out Kc for the backward reaction from the other Kc value?
1/ Kc
What does an equilibrium constant in terms of concentration apply to?
When all the reactants and products are in the same phase, a homogenous equilibria
What is partial pressure?
The pressure that the gas would have if it occupied the volume alone
How can partial pressure be worked out?
Pa = (no. mol of a/total mol) x total pressure
What is Kp for the reaction:
aA + bB –> cC + dD
p(C)^c x p(D)^d
p(A0^a x p(B)^b
What is a heterogenous equilibria called?
An equilibria which exists in more than one phase
Why are solids not included in K?
‘Concentrations’ of solids are constant so are removed
What does a very large value of K (K>1x10^10) show about the extent of reaction?
Reaction proceeds almost to completion, leaving very small amounts of reactants at equilibrium
Position of equilibrium lies to the right
What do a very small value of K (K
Reaction hardly occurs, producing very small quantities of products at equilibrium
Position of equilibrium lies to the left
What do values around 1 of K show?
Concentrations of reactions and products are almost the same at equilibrium
How do you determine an equilibrium constant?
Combine known quantities under controlled conditions and allow them to go to equilibrium
Accurately measure the conc in the mixture to allow to you to calculate the other concs
Substitute into equilibrium expression and calculate
