Chapter 19 - Equilibrium Flashcards
What is homogeneous equilibria?
Equilibrium species all have the same state which are gases or aqueous
What is heterogeneous equilibria?
Equilibrium species have different states which can be solid, liquid or gas
Which species are omitted from Kc expression?
Solid and liquid
What can also be used instead of moles in the mole fractions of Kp expression?
Volumes
How to calculate mole fraction?
Mole fraction x(A) = Number of moles of A ÷ total number of moles in gas mixture
What must all the mole fractions total to?
One
How to calculate partial pressure (p)?
Partial pressure (p) = mole fraction x total pressure (P)
What must all the partial pressure total to?
Total pressure
What is the only factor that can change the value of K?
Temperature
What happens to K when temperature is increased (forwards reaction: exothermic)?
Decreases
Explain the equilibrium shift when temperature is increased (forwards reaction: exothermic)
Equilibrium shifts to LEFT
(P) decreases
(R) increases
K decreases
What happens to K when temperature is increased (forwards reaction: endothermic)?
Increases
Explain the equilibrium shift when temperature is increased (forwards reaction: endothermic)
Equilibrium shifts to RIGHT
(P) increases
(R) decreases
K increases
What is the effect of changing concentration on value of K?
No effect, however equilibrium shift still occurs to correct the system
What happens to the ratio of Kc or Kp when concentration of REACTANT increases?
Ratio of equilibrium expression is LESS than Kc or Kp as K decreases
What corrects the equilibrium constant when the concentration of reactant increases?
- Concentration of PRODUCT must INCREASE
- Concentration of reactant must decrease
What happens to the ratio of Kc or Kp when concentration of PRODUCT increases?
Ratio of equilibrium expression is MORE than Kc or Kp as K increases
What corrects the equilibrium constant when the concentration of product increases?
- Concentration of REACTANT must INCREASE
- Concentration of product must decrease
What is the effect of changing pressure on the value of K?
No effect, however equilibrium shift still occurs to correct the system
What will doubling the pressure do to the partial pressures and concentrations of the reactants and products?
Doubles them BOTH
What is the effect of a pressure change on K when there is GREATER mol of PRODUCT?
Increases
What corrects the equilibrium constant after pressure change when there is GREATER mol of PRODUCT?
Products decrease
Reactants increase
Equilibrium shifts to LEFT
What is the effect of a pressure change on K when there is GREATER mol of REACTANT?
Decreases
What corrects the equilibrium constant after pressure change when there is GREATER mol of REACTANT?
Products increase
Reactants decrease
Equilibrium shifts to RIGHT
What is the effect of a catalyst on the value of K?
No effect as only rate is affected and not the equilibrium
