Question

(a) Explain, with example, how the physical states of the reactants and products can be shown in a chemical equation.
(b) Balance the following equation and add state symbols:
$\mathrm{Zn}+\mathrm{HCl}\underset{}{\to }{\mathrm{ZnCl}}_2+{\mathrm{H}}_2$
(c) Convey the following information in the form of a balanced chemical equation:
"An aqueous solution of ferrous sulphate reacts with an aqueous solution of sodium hydroxide to form a precipitate of ferrous hydroxide and sodium sulphate remains in solution."

Answer 1

(a) Physical state of reactants and products can be shown by writing (s) for solid, (l) for liquid, (aq) for aqueous solution and (g) for gaseous substance after its formula or symbol in chemical reaction.
Example:
C (s) + O₂ (g) $\to$ CO₂ (g) + HEAT
Here, Carbon is taken in solid state and carbon dioxide and oxygen are in gaseous state.

(b) Zn (s) + 2HCl (aq) $\to$ ZnCl₂ (aq) + H₂ (g)

(c) FeSO₄ (aq) + 2NaOH (aq) $\to$ Fe(OH)₂ (s) + Na₂SO₄ (aq)