Question

When an excess of ${\mathrm{CO}}_2$ is passed through lime water then what will be the sequence of the product?

• A. $\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2,\mathrm{CaO}$
• B. $\mathrm{CaO},\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$
• C. ${\mathrm{CaCO}}_3,\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$
• D. $\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2,{\mathrm{CaCO}}_3$

Answer 1

The correct option is C

${\mathrm{CaCO}}_3,\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$

• When an excess of ${\mathrm{CO}}_2$ (Carbon dioxide) is passed through lime water($\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$), the following reaction will takes place:$$\begin{gathered} \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ (\mathrm{Lime}\mathrm{water})(\mathrm{Carbon}\mathrm{dioxide})(\mathrm{Calcium}\mathrm{carbonate})\left(\mathrm{Water}\right) \end{gathered}$$.
• Again when ${\mathrm{CO}}_2$ is passed through the formed product, we get:$$\begin{gathered} {\mathrm{CaCO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to \mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2\left(\mathrm{aq}\right) \\ (\mathrm{Calcium}\mathrm{carbonate})\left(\mathrm{Water}\right)(\mathrm{Carbon}\mathrm{dioxide})(\mathrm{Calcium}\mathrm{bicarbonate}) \end{gathered}$$.
• Hence, the correct sequence of product formation is ${\mathrm{CaCO}}_3,\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$.

Therefore, among the above given options, option (c) is correct.