What is meant by "chemical equilibrium"?

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.