Reversible Reaction
Definition and meaning of Reversible Reaction in chemistry.
A reversible reaction is a chemical reaction in which products can react with each other to reform the original reactants, with both forward and reverse reactions occurring simultaneously. The reaction reaches chemical equilibrium when the rate of the forward reaction equals the rate of the reverse reaction.
In more detail
In a reversible reaction, the products don't remain isolated from reactants. Instead, a dynamic equilibrium is established where both directions proceed at equal rates, resulting in constant concentrations of reactants and products. This is distinct from irreversible reactions, which proceed to completion in only one direction. Reversible reactions are represented with a double arrow (⇄) to show that both directions are possible. The position of the equilibrium depends on factors like temperature, pressure, and concentration, governed by Le Chatelier's principle.
Key facts
| Field | Physical Chemistry |
|---|---|
| Notation | Double arrow (⇄) between reactants and products |
| Example | H2 + I2 ⇄ 2HI |
| Equilibrium condition | Forward and reverse reaction rates are equal |
The reaction between hydrogen and iodine gas is reversible: H2 + I2 ⇄ 2HI. At equilibrium, hydrogen, iodine, and hydrogen iodide all coexist in the reaction vessel, with the forward and reverse reactions occurring at equal rates.
Frequently asked questions
What is the difference between a reversible and irreversible reaction?
A reversible reaction can proceed in both directions and reaches equilibrium, while an irreversible reaction proceeds to completion in only one direction, with products not reforming reactants under normal conditions.
Does equilibrium mean the reaction has stopped?
No, equilibrium is a dynamic state where both forward and reverse reactions continue occurring at equal rates at the molecular level, but there is no net change in the amounts of reactants and products.