Question

Select the combination reactions between: (i) elements, (ii) compounds and (iii) an element and a compound, for the given reaction.

$$\begin{gathered} \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right) \\ \mathrm{Calcium}\mathrm{Carbon}\mathrm{Calcium} \\ \mathrm{oxide}\mathrm{dioxide}\mathrm{carbonate} \end{gathered}$$

Answer 1

Combination reaction:

The reactions in which a combination of two or more substances occurs to give the products are known as combination reactions. There can be combination reactions of elements, compounds, or both.

Elements and compounds:

Elements are substances consisting of atoms. They are pure substances that cannot be broken down into simpler ones.

Compounds are substances composed of more than one element in it and can be broken down into simpler ones.

Given equation:

The given reaction is a combination reaction of two compounds, that are, Calcium oxide $\left(\mathrm{CaO}\right)$ and Carbon dioxide $\left({\mathrm{CO}}_2\right)$ to give Calcium carbonate $\left({\mathrm{CaCO}}_3\right)$.

$$\begin{gathered} \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right) \\ \mathrm{Calcium}\mathrm{Carbon}\mathrm{Calcium} \\ \mathrm{oxide}\mathrm{dioxide}\mathrm{carbonate} \end{gathered}$$

Therefore, the given reaction is the combination reaction between (ii) compounds.