Question

A student dropped few pieces of marble in dilute hydrochloric acid contained in a testtube. the evolved gas was passed through lime water. what change would be observed in lime water

Answer 1

  The evolved gas will be Co2


    When you pass this gas then it will form a milkish appearance due to the formation of CaCO3

             Ca(OH)2+CO2 ------------- Caco3 +h20

Answer 2

When dilute HCl is added to marble which is calcium carbonate, it forms calcium chloride, water and carbon dioxide. The chemical equation for the reaction is as follows: CaCO3 + 2HCl → CaCl2 + H2O + CO2

Carbon dioxide gas turns lime water milky due to the formation of calcium carbonate.

The chemical equation showing the reaction between lime water and carbon dioxide is as follows: Ca(OH)2 + CO2 → CaCO3 + H2O