Equilibrium Flashcards
What type of reactions does equilibria concern
Reversible reactions
When is a dynamic equilibria reached
When the rate of the forward reaction is the same as the rate of the reverse reaction
What is Le Chateliers’s principle
If the conditions of an equilibrium in a closed system are changed, the equilibrium will shift to oppose that change
How does changing the concentration affect the equilibria
Increasing concentration on the left will shift the equilibria right
How does changing the pressure affect the equilibria
Changing the pressure favours the side of the reaction with the fewest moles in reactions solely involving gases
How does changing the temperature affect the equilibria
If the forward reaction is exothermic, then the reverse will be endothermic. Therefore, increasing the temperature favours the reverse reaction and vice versa
How does a catalyst affect the equilibria
No effect on the position of the equilibria but decreases the time taken to establish the equilibria.
How do you calculate the Kc
Concentrations of reactants multiplied and divided by the concentrations of products, raised to the power of their moles
What must you also calculate when calculating Kc
Units
How is Kc affected by the position of the equilbiria
If the equilibria is shifted to the left, Kc decreases, if Kc shifts to the right, Kc increases
What is the definition of an acid
Proton donor
What is the definition of a base
Proton acceptor
What is the difference between strong and weak acids
Strong acids fully dissociate from their hydrogen ions
Define pH
-log(H+)
Calculate pH of 0.3 mol/dm3 of sulphuric acid
0.2
