CBSE Class 10 Answered
To make a chemical equation more informative, the physical states of the reactants and products are mentioned along with their chemical formulae.
The gaseous, liquid, aqueous and solid states of the reactants and products are represented by the notations (g), (l), (aq) and (s) respectively.
The word aqueous (aq) is written if the reactant or product is present as a solution in water.
For example, oxygen, hydrogen, sulphur dioxide, hydrogen sulphide etc. are gases. Hence, they are represented by (g) next to their formula generally in lowercase.
O2(g) H2(g) SO2(g) H2S(g)
Similarly, Carbon, copper, zinc etc re in solid state. Therefore their physical states can be represented as C(s) Cu(S) Zn(s)
Zinc sulphate solution, Copper sulphate solution, Sodium hydroxide, water etc atr in liquid state. Therefore their physical states can be represented by ZnSO4(l) CuSO4(l) NaOH(l) H2O(l)