Question

Write the chemical name of (a) Lime water and (b) the white insoluble solid formed on the reaction of carbon dioxide with lime water.

Answer 1

Chemical name:

• A chemical name is a systematic name given to a chemical compound.
• The worldwide using chemical names are created and developed by IUPAC (International Union for Pure and Applied chemistry).

(a) Lime water:

• The chemical name of lime water is calcium hydroxide $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$.
• It is also called slaked lime.
• It is clear and colourless.
• It is basic in nature.
• Lime water can be prepared by the reaction of calcium with water.

$\mathrm{Ca}\left(\mathrm{s}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)+\mathrm{Heat}$

(b)

• The white insoluble solid formed in the reaction of carbon dioxide with water is calcium carbonate ${\mathrm{CaCO}}_3$.

$$\begin{gathered} \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ (\mathrm{Lime}\mathrm{water})(\mathrm{Carbon}(\mathrm{Calcium}\left(\mathrm{Water}\right) \\ \mathrm{dioxide})\mathrm{carbonate}) \end{gathered}$$

• When carbon dioxide is bubbled through lime water, the lime water turns milky.
• It is a characteristic test for carbon dioxide.