(a) What happens when an acid reacts with a metal carbonate? Explain with the help of an example. Give chemical equation of the reaction involved. (b) What happens when carbon dioxide gas is passed through lime water? (i) For a short time? (ii) For a considerable time? Write equations of the reactions involved. Solutions: (a) When an acid reacts with metal carbonate, it results to the formation of a salt, carbon dioxide and water.
ChemistryClass 10ICSEAnswered 27 Mar 2026
Answer
Example: when dilute hydrochloric acid reacts with sodium carbonate, then sodium chloride, carbon dioxide and water are formed
Na2CO3(s) + 2HCl (aq) → 2NaCl(aq) + CO2 (g) + H2O(l)
(b)(i) When carbon dioxide is passed through lime water, lime water turns milky.
Ca(OH)2 + CO2 → CaCO3 + H2O
(ii) Lime water solution becomes clear CaCO3 + CO2 + H2O → Ca(HCO3)2