Question

Which of the following metals can be used for liberating hydrogen from dilute hydrochloric acid? Write reactions as well.

1. Zinc
2. Copper
3. Iron
4. Silver
5. Magnesium

Answer 1

• Zinc, Magnesium and iron can easily displace hydrogen from dilute hydrochloric acid. Because these metals are highly reactive in nature whereas, silver and copper lies below hydrogen in the reactivity series. So these metals are not able to displace hydrogen from acids.
• The reaction between Zinc and Hydrochloric acid. $$\begin{gathered} \mathrm{Zn}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\stackrel{}{\to }{\mathrm{ZnCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_{2\left(\mathrm{g}\right)} \\ \mathrm{Zinc}\mathrm{Hydrochloric}\mathrm{acid}\mathrm{Zinc}\mathrm{chloride}\mathrm{Hydrogen} \end{gathered}$$
• The reaction between Magnesium and dilute hydrochloric acid. $$\begin{gathered} \mathrm{Mg}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\stackrel{}{\to }{\mathrm{MgCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{Magnesium}\mathrm{Hydrochloric}\mathrm{acid}\mathrm{Magnesium}\mathrm{chloride}\mathrm{Hydrogen} \end{gathered}$$
• The reaction between Iron and dilute hydrochloric acid.
• $$\begin{gathered} \mathrm{Fe}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\stackrel{}{\to {\mathrm{FeCl}}_2}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{Iron}\mathrm{Hydrochloric}\mathrm{acid}\mathrm{Ferrous}\mathrm{chloride}\mathrm{Hydrogen} \end{gathered}$$