i.
To
make a chemical equation more informative, the physical states of the reactants
and products are mentioned along with their chemical formulae.
ii.
The
gaseous, liquid, aqueous and solid states of reactants and products are
represented by the notations (g), (l), (aq) and (s) respectively.
iii.
The
word aqueous (aq) is written if the reactant or product is present as a
solution in water.
