What are the features of dynamic equilibrium?
- The reversible reaction has a forward and a reverse
- Happens in a closed system
- rate of forward = rate of backwards reaction
- No change in macroscopic properties ( colour/pH)
What are the features of a physical equilibrium?
- In a closed system only
- involves changes of state
- rate of evaporation = rate of condensation
What is Kc?
A constant for a reaction at a specific temperature
What does Kc tell us?
How far a reaction must proceed
What happens if kc is small?
Equilibrium lies to the left
What does it mean if Kc=1?
There are equal concentrations of reactants and products
What can Kc only be affected by?
Temperature
Le Chatelier’s principle for pressure
- only affects equilibrium position if there are different amount of gaseous molecules on both sides
- if you increase pressure equilibrium shifts to the side with fewer gaseous molecules to decrease the pressure
- if you decrease pressure equilibrium shifts to the side with more gaseous molecules
Le Chatelier’s principle for concetration
- ## increase the reactant equilibrium shifts to the right or to the side with fewer moles of solute
Le Chatelier’s principle for concetration
- ## increase the reactant equilibrium shifts to the right or to the side with fewer moles of solute
What is Le Chatelier’s principle?
When a system at equilibrium is subjected to a change the system will respond to minimise the effect of that change
What is Q expressed with?
Non equilibrium concentrations
What happens if Kc is more than Q
Reaction will proceed to the right to produce more products and to increase Q
What happens if Q=Kc?
The reaction is at equilibrium so no change will take place
