Question: Giving an example list two information which make a chemical equation more useful (informative).
Answer:
(i) Physical state of reactants must be mentioned, e.g.
2H (g) + O₂(g) → 2H₂0 (l)
(ii) Condition in which reaction takes place are written on the arrow head, e.g.
2H₂ (g) + O₂ (g) (burning) → 2H₂0 (l)
Consider the following chemical reaction
X + Barium chloride → Y + Sodium chloride
(White ppt)
(a) Identify ‘X’ and ‘Y’
(b) The type of reaction
(a) ‘X’ is Na₂SO₄ and Y is BaSO₄.
(b) The type of reaction
Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl (White ppt)
The reaction is precipitation reaction. It is also called double displacement reaction.