Question

What happens when (a) Dilute sulphuric acid is poured on a copper plate? (b) Iron nails are placed in a copper sulfate solution? Write word equations of the reactions involved.

Answer 1

(a) Reaction of copper with dilute sulfuric acid:

• When sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ is poured on the metallic plate made up of copper $\left(\mathrm{Cu}\right)$, then copper sulfate $\left({\mathrm{CuSO}}_4\right)$ formed along with the liberation of sulfur dioxide $\left({\mathrm{SO}}_2\right)$gas. Water is also produced in this reaction.
• The chemical equation for this reaction can be depicted as:

$\mathrm{Cu}\left(\mathrm{s}\right)+2{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{CuSO}}_4\left(\mathrm{aq}\right)+{\mathrm{SO}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

• The word equation for this reaction can be depicted as:

$\mathrm{Copper}\left(\mathrm{solid}\right)+\mathrm{Sulfuric}\mathrm{acid}\left(\mathrm{aqueous}\right)\to \mathrm{Copper}\mathrm{sulfate}\left(\mathrm{aqueous}\right)+\mathrm{Sulfur}\mathrm{dioxide}\left(\mathrm{gas}\right)+\mathrm{Water}\left(\mathrm{liquid}\right)$

(b) Reaction of Iron with Copper sulfate:

• When iron $\left(\mathrm{Fe}\right)$ nails are placed in Copper sulfate $\left({\mathrm{CuSO}}_4\right)$ solution, iron sulfate $\left({\mathrm{FeSO}}_4\right)$ is formed along with copper $\left(\mathrm{Cu}\right)$ metal.
• This type of reaction is known as displacement reaction.
• Iron is placed above copper in the activity series, thus it can displace copper from its solution.
• The chemical equation can be depicted as:

$\mathrm{Fe}\left(\mathrm{s}\right)+{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)\to {\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right)$

• The word equation for this reaction can be depicted as:

$\mathrm{Iron}\left(\mathrm{solid}\right)+\mathrm{Copper}\mathrm{sulfate}\left(\mathrm{aqueous}\right)\to \mathrm{Iron}\mathrm{sulfate}\left(\mathrm{aqueous}\right)+\mathrm{Copper}\left(\mathrm{solid}\right)$