Reversible reactions
Reversible Reactions ⇌ : reactions which can go both ways, depending on the conditions.
Example: CuSO4.5H2O (blue) ⇌ CuSO4(white) + H2O
(to get anhydrous you heat it, & to get the hydrated form, just add water) There are two types of equilibrium: static and dynamic.
Dynamic equilibrium (FIY on the mock, these were the points you needed for the definition of equilibrium):
- Rate of forward reaction = rate of reverse reaction
- Concentrations of all reactants and products remain
- The system is closed, and on the large scale (macroscopic) everything is
If the conditions of an equilibrium are changed, the position of the equilibrium moves to oppose the change (this is known as Châtelier’s Principle, if you know this, you can extrapolate how the conditions below will affect an equilibrium):
–TEMPERATURE: If the temperature is lowered – the equilibrium moves in the exothermic direction. If the temperature is raised – the equilibrium moves in the endothermic direction.
–PRESSURE: If the pressure is raised the equilibrium moves to reduce pressure, to the side with fewest gas molecules. If the pressure is lowered the equilibrium moves to the side with most gas molecules.
–CONCENTRATION: Decreasing reactant concentration or increasing product concentration moves equilibrium to the reactant side. Increasing reactant concentration or decreasing product concentration moves it to the product side.
NOTE CATALYSTS DO NOT CHANGE THE POSITION OF THE EQUILIBRIUM; THE REACTION JUST ARRIVES AT THE EQUILIBRIUM FASTER.