Chemical Equilibria Flashcards
What is enthalpy?
Energy change per mol.
If a reaction is exothermic in one direction, what is it in the other direction?
Endothermic.
What is equilibrium?
When the rates of the forwards and backwards reactions are the same.
What factors affect dynamic equilibrium?
- Temperature
- Pressure (in gases)
- Concentration
- Catalyst (doesn’t affect position of equilibrium)
What is Le Chatelier Principle?
If a system is at equilibrium and a change is made to any of the conditions, then the system responds to counteract the change.
How does temperature affect equilibrium?
- An increase in temperature favours the endothermic direction.
- A decrease in temperature favours the exothermic direction.
How does pressure affect equilibrium?
- An increase in pressure favours the direction which produces the least moles.
- A decrease in pressure favours the direction which produces the most moles.
How does concentration affect equilibrium?
- Increasing concentration shifts the equilibrium to the opposite side.
- Decreasing concentration shifts the equilibrium to the same side.
How does a catalyst affect equilibrium?
An addition of a catalyst doesn’t change the position of equilibrium. It speeds both reactions up equally so they reach equilibrium quicker.
What is the only thing that affects the value of Kc for a particular reaction?
Temperature.
