Question

What happens when diluting hydrochloric acid is added to iron filling?

Answer 1

The reaction of metal with acid

• The metal reacts with an acid to form its corresponding salt along with hydrogen gas.
• The general chemical reaction is as follows,
• $\mathrm{Metal}+\mathrm{Acid}\to \mathrm{Salt}+{\mathrm{H}}_2\left(\mathrm{g}\right)$
• The gas produced burns with a pop sound, confirming the gas to be hydrogen gas.

The chemical reaction of iron filling with hydrochloric acid

• When iron filings$\left(\mathrm{Fe}\right)$ are added to dilute hydrochloric acid$(\mathrm{dil}.\mathrm{HCl})$, ferrous chloride$\left({\mathrm{FeCl}}_2\right)$ and hydrogen gas are formed.
• The chemical reaction is as follows,
• $$\begin{gathered} \mathrm{Fe}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{FeCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \left(\mathrm{Iron}\right)(\mathrm{Hydrogen}\mathrm{chloride})(\mathrm{Ferrous}\mathrm{chloride})(\mathrm{Hydrogen}\mathrm{gas}) \end{gathered}$$