Reversible reactions can go fowards or backwards.
The directions depends on conditions such as:
When a reaction reaches Equilibrium All the reactants and products are present in the Equilibrium mixture. The amounts of the reactants and products dont change from there on.
When a reaction reaches Equilibrium it is shown with this symbol:
Different Equilibrium reactions have different points of Equilibrium.
For strong acid Equilibrium lies on the right.
For weak acids Equilibrium lies on the left.
In Dynamic Equilibrium the fowards and backwards reaction happens at the same time.
They both happen at the same rate. This explains why the amounts of chemicals in the reaction do not change.
Strong and Weak acids
In strong acids most molecules from the reaction Ionize. So Equlibrium lies on the right.
In Weak acids very few molecules from the reactant Ionize. So Equilibrium lies on the left.