6.6- THE EFFECT OF CHANGING CONDITIONS ON EQUILIBRIA Flashcards
What is the effect on Kc, effect on products, effect on reactants + direction of change on equilibrium when temperature is decreased for an endothermic reaction?
effect on Kc- decrease
effect on products- decrease
effect on reactants- increase
direction of change of equilibrium- moves left
What is the effect on Kc, effect on products, effect on reactants + direction of change on equilibrium when temperature is increased for an endothermic reaction?
effect on Kc- increase
effect on products- increase
effect on reactants- decrease
direction of change of equilibrium- moves right
What is the effect on Kc, effect on products, effect on reactants + direction of change on equilibrium when temperature is increased for an exothermic reaction?
effect on Kc- decrease
effect on products- decrease
effect on reactants- increase
direction of change of equilibrium- moves left
What is the effect on Kc, effect on products, effect on reactants + direction of change on equilibrium when temperature is decreased for an exothermic reaction?
effect on Kc- increase
effect on products- increase
effect on reactants- decrease
direction of change of equilibrium- moves right
What happens to equilibrium if equilibrium constant Kc increases in value?
equilibrium moves to right, that is, forward direction (more products)
What happens to equilibrium constant Kc decreases in value?
equilibrium moves to left, that is, backward direction (less products)
What is the general rule for equilibrium constant for an exothermic reaction when increasing temperature?
decreases equilibrium constant
What is the general rule for equilibrium constant for an endothermic reaction when increasing temperature?
increases equilibrium constant
How will equilibrium change for an exothermic reaction, when the temperature is increased?
will move equilibrium to left
How will equilibrium change for an endothermic reaction, when the temperature is increased?
will move equilibrium to right
When does the equilibrium constant not change?
if temp not changed
What can the size of the equilibrium constant Kc tell us about?
composition of equilibrium mixture
If the Kc is much greater than 1 what does this mean?
products predominate over reactants + equilibrium position is over to right
If the Kc is much less than 1 what does this mean?
reactants predominate + equilibrium position is over to left
What are reactions where equilibrium constant greater than 10^10 usually regarded as?
usually regarded as going to completion
What are reactions where equilibrium constant of less than 10^-10 regarded as?
not taking place at all
What effect do catalysts have on value of Kc?
no effect on value of Kc
Why do catalysts not have an effect on the value of Kc?
as they affect rates of both forward + back reactions equally
How do catalysts affect the rate of both forward + backward reactions equally?
reducing activation energy for reactions
What DO catalysts affecr?
rate at which equilibrium attained- important in industrial processes
In what phase can reversible reactions take place in?
gas phase + in solution
How are the gaseous equilibria concentrations expressed differently?
using partial pressure rather than concentrations
