An equilibrium state means a state in which all significant factors and processes remain more or less constant over a period of time.
Cato Maximilian Guldberg (1836–1902) and Peter Waage (1833–1900) first proposed the equilibrium law in 1864.
Equilibrium law - the mathematical description of a chemical system at equilibrium.
When a mixture of reactants and products of a reaction reaches equilibrium at a given temperature, its equilibrium constant always has the same value.
The equilibrium law is sometimes called the law of mass action.
Le Châtelier’s principle - a generalization that states that:
chemical systems at equilibrium shift to restore equilibrium when a change occurs that disturbs the equilibrium.
An adjustment by a system at equilibrium that results in a change in the concentrations of reactants and products is called an equilibrium shift.
Le Châtelier’s principle allows chemists to predict the qualitative effects of changes in concentration, pressure, and temperature on a chemical reaction system at equilibrium.
| Strong Acid/Base | Weak Acid/Base |
|
Strong acid - ionise/dissociate completely producing H+ ion Strong base - ionise/dissociate completely producing OH- ion All are in ions state, No molecule left Strong electrolyte with high conductivity |
Weak acid - ionise/dissociate partially producing H+ ion Weak base - ionise/dissociate partially producing OH- ion Most in undissociated molecule form Poor electrolyte with low conductivity |
| HCl → H+ + Cl- | CH3COOH ⇌ H+ + CH3COO- |
