Question

The chemical change involving iron and hydrochloric acid illustrates a __ reaction.

Answer 1

1. When in a reaction, a higher reactive metal displaces a lower reactive metal from its compound in an aqueous solution, it is said to be a displacement reaction.
2. This is an irreversible reaction because once the higher reactive metal substitutes the low reactive metal, the lower reactive metal won't be able to displace the former one.
3. The chemical reaction involved is;

$$\begin{gathered} \mathrm{Fe}\left(\mathrm{s}\right)+\mathrm{HCl}\left(\mathrm{l}\right)\to {\mathrm{FeCl}}_2\left(\right(\mathrm{s})+{\mathrm{H}}_2(\mathrm{g}\left) \\ \right(\mathrm{Iron}\mathrm{II})(\mathrm{Hydrochloric}(\mathrm{Ferrous} \\ \mathrm{acid})\mathrm{chloride}) \end{gathered}$$

Hence, the chemical change involving iron and hydrochloric acid illustrates a displacement reaction.