What is meant by "chemical equilibrium"?

Expert Answers
boblawrence eNotes educator| Certified Educator

Chemical Equilibrium is a term applied to reversible chemical reactions.  It is the point at which the rate of the forward reaction is equal to the rate of the reverse reaction.  When equilibrium is achieved, the concentrations of reactants and products become constant.

Because the forward and reverse reactions are continuously occurring, but in equilibrium at an equal rate, the situation is described as a Dynamic Equilibrium.  The equilibrium can be altered by adding reactant, removing product, or changing conditions such as temperature.

soph727 | Student

Chemical equilibrium means:

Its a reversible equation which is an incomplete reaction eg (double arrows)

H2 + I2 --> 2HI


At equilibrium, the rate of the forward reaction equals the rate of the reverse reaction of physics equilibrium is a static process eg tug or war. Chemical equilibrium is a dynamic process.

Equilibrium is characterised by

  1. Constancy of macroscopic properties ie colour remains the same
  2. Rate of forward and reverse reactions is equal.

Bascily, if you put in more reactant, the equation will be favoured forwards as the system wants to use it up to produce more product.

If you put more product in, reverse will be favoured.

[reactants] increase, forward favoured

[reactants] decrease reverse favoured

[products] increase reverse favoured

[products] decrease forward favoured.