Chapter 10 - Chemical equilibrium (L) Flashcards
What is chemical equilibrium?
When the forward and backwards reactions are occurring at equal rates
What 2 things must the reaction be for equilibrium to be reached?
- The reaction must be closed (i.e. nothing being added or removed)
- The reaction must be reversible
What is Le Chatelier’s principle?
If a reaction is at equilibrium, and the reaction conditions are then changed, the equilibrium position will shift in the direction that opposes the applied change
What are the 3 changes that affect position of equilibrium?
- Pressure
- Temperature
- Concentration of reactants/products (material either added or removed)
What is the effect on equilibrium position when reactants are added?
Shifts to right to get rid of added reactants
What is the effect on equilibrium position when reactants are removed?
Shifts to left to produce more reactants
What is the effect on equilibrium position when product is added?
Shifts to left to get rid of added product
What is the effect on equilibrium position when product is removed?
Shifts to the right to produce more product
When do changes in pressure affect the position of the equilibrium?
For reactions that involve gases
What is the effect on equilibrium position when the temperature is increased on a forward exothermic reaction?
The equilibrium will move to the left (in the endothermic backwards direction) to lower the temperature
What is the effect on equilibrium position when the temperature is decreased on a forward exothermic reaction?
The equilibrium will move to the right (in the exothermic forward direction) to increase the temperature
What is the effect on equilibrium position when the pressure is increased?
The equilibrium will shift to the side with the fewer moles of gas to lower the pressure
What is the effect on equilibrium position when the pressure is decreased?
The equilibrium will shift to the side with more moles of gas
What is the effect on equilibrium position when the pressure is decreased?
The equilibrium will shift to the side with more moles of gas
What is the effect on equilibrium position when a catalyst is added?
There is no effect on the position of the equilibrium
What happens when a catalyst is added to a reaction in dynamic equilibrium?
The speed of both the forward and backwards reactions increase- it helps the reactions form equilibrium faster