Equilibria Flashcards
What does K stand for ?
Equilibrium constant
What does Kc stand for
Equilibrium constant using concentration
What does Kp stand for
Equilibrium constant using pressure
What does [ ] represent
Concentration
Mole fraction of a gas =
Moles (gas) / total moles (gas) in mixture
Partial pressure of a gas =
Mole fraction (gas) x total pressure
what is dynamic equilibrium ?
RATE forward reaction = RATE back wards reaction (conc of reactants and products stay constant)
Give Le Chatelier’s principle for concentration
increasing conc of reactants will make more product (vice versa) - decreasing conc has opposite effect
Give Le Chatelier’s principle for pressure
increasing pressure shifts equilibrium to side with fewer GAS molecules
Give Le Chatelier’s principle for temperature
increasing temp will shift equilibrium in endothermic direction
how do catalysts affect equilibrium ?
cannot affect position of equilibrium, however they do cause equilibrium to be reached faster
what is the Kc expression ?
aA+bBdD+eE
[D]^d[E]^e
————–
[A]^a[B]^b
The larger Kc is …
the further to right equilibrium lies
The smaller Kc is …
the further to left equilibrium lies
a dynamic equilibrium can only happen if …
system is closed and temp is constant
what is a homogeneous reaction ?
all the reactants and products are the same
what is a heterogeneous reaction ?
products and reactants in different states
what substances apply to the Kc expression ?
only gaseous and aqueous substances (not liquids/solids)
define total pressure
sum of all the partial pressures of individual gases
what does p( ) represent ?
partial pressure of …
Kp =
p(A)^a p(B)^b
what changes the equilibrium constant ?
temp
if temp shifts equilibrium to left, what happens to equilibrium constant ?
constant decreases
if temp causes equilibrium to shift to right, what happens to equilibrium constant ?
constant increases
Kc and Kp are only affected by …
temperature
state two features of a system that is in dynamic equilibrium
rate of forwards = rate of backwards
concentrations are constant but constantly interchanging
when describing equilibrium what word to use ?
favours
state le Chatiliers principle
when the conditions on a system in equilibrium are changed, the equilibrium moves to minimise the effects of the change
