Question

a student dropped a few piece of marble in dilute hydrochloric acid contained in a test tube the evolved gas was then passed for a long time through lime water what changes would be observed in lime water write balanced equation for both the changes observed

Answer 1

marble (CaCO3) + HCl= CaCl2 + CO2 + H20.
the gas released hence was CO2, carbon dioxide. when the gas was passed through lime water, it turned lime water milky.

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