(a) What are the various ways in which a chemical equation can be made more informative? Give examples to illustrate your answer.
(b) Write balanced chemical equation from the following information:
An aqueous calcium hydroxide solution (lime water) reacts with carbon dioxide gas to produce a solid calcium carbonate precipitate and water.
(a) The various ways in which a chemical equation can be made more informative are:
(i) By indicating the physical states of the reactants and products.
Example: Gaseous state is indicated by the symbol (g).
Zn (s) + H2SO4 (aq) → ZnSO4 (aq) + H2 (g)
(ii) By indicating the heat changes taking place in the reaction.
For example: An exothermic reaction is indicated by writing “+Heat” or “+Heat energy” or “+Energy” on the products side of an equation.
C (s) + O2 (g) → CO2 (g) + Heat
(iii) By indicating the “conditions” under which the reaction takes place.
Example: Delta stands for heat which is written over the arrow of the equation.
2KClO3(s) + heat + MnO2 → 2KCl(s) + 3O2(g)
(b) Ca(OH)2 (aq) + CO2(g) → CaCO3(s) + H2O(l)