Question

What would you observe when: Hydrochloric acid is added to calcium carbonate?

Answer 1

Chemical reaction:

• When hydrochloric acid is added to calcium carbonate, calcium chloride and carbon dioxide gas are formed.
• ${\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{CaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\uparrow$

Observation:

• Carbon dioxide passed into limewater gives a milky solution. This is due to the insoluble suspension of calcium carbonate formed.
• $$\begin{gathered} \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Lime}\mathrm{water}\mathrm{Carbon}\mathrm{Calcium}\mathrm{Water} \\ \mathrm{oxide}\mathrm{carbonate} \\ (\mathrm{Milky}\mathrm{white}\mathrm{solution}) \end{gathered}$$