3.1.6 Chemical equilibria and Kc Flashcards
What is meant by dynamic equilibirum?
- Rate of forward reaction is equal to the rate of the backward reaction
- Concentrations of products and reactents stay constant
Why is a closed system used?
Stops chemicals entering/leaving
What is meant by dynamic?
What is Le Chatelier’s Principle?
If a change is made to a system in dynamic equilibrium, then the position of equilibrium will move to oppose the change
How does equilibrium change when the concentration of a reactant is increased/decreased?
Increased = equilibrium shifts to the right to oppose the increased concentration of the reactant and produce more products
Decreased = equilibrium shifts to the left to oppose the decreased concentraton of the reactents and produce more reactants
How does equilibrium change if the temperature of the system is increased/decreased?
Increased = equilibrium favours the endothermic reaction to oppose the increase in temperature
Decreased = equilibrium favours the exothermic reaction to oppose the decrease in temperature
How does equilibrium change if the pressure of the system is increased/decreased?
Increased = equilibrium shifts to the side with the fewest moles of gas in order to oppose the increase in pressure
Decreased = equilbilibrium shifts to the side with the most moles of gas in order to oopose the decrease in pressure
What is the effect of a catalyst on equilibrium?
None
How do you calculate Kc of the following reaction:
aA + bB ⇌ cC + dD
Kc = ([C]^c [D]^d) / ([A]^a [B]^b)
What compounds are ignored in equilibrium constant expressions?
Pure liquids and solids
What is the only factor that can impact Kc?
Temperature
