Question

how the physical state of reactants and products represented in equation?

Answer 1

The physical state of reactants and product is written aside the substance in a chemical equation. However it is not compulsory.
If it is , Solid (S)
LIQUID (L)
Aqueous (aq)
gaseous (g) is written there.
Eg:- C (s) +O2 (g) ------Co2(g)
H2(g) +O2. (g) ----------H2O. (L)

Answer 2

Answer:

The physical state of reactants and product is written aside the substance in a chemical equation. However it is not compulsory.

If it is , Solid (S)

LIQUID (L)

Aqueous (aq)

gaseous (g) is written there.

Eg:- C (s) +O2 (g) ------Co2(g)

H2(g) +O2. (g) ----------H2O.(L)