Question

Which acid is formed when concentrated nitric acid reacts with sulfur?

Answer 1

Reaction of Sulfur with Nitric acid:

• When Sulfur reacts with concentrated nitric acid$\left({\mathrm{HNO}}_3\right)$, sulfuric acid$\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ is formed along with water$\left({\mathrm{H}}_2\mathrm{O}\right)$, and nitrogen dioxide$\left({\mathrm{NO}}_2\right)$ gas is liberated.
• The chemical reaction can be depicted as:

$\mathrm{S}\left(\mathrm{s}\right)+6{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+6{\mathrm{NO}}_2\left(\mathrm{g}\right)$

Role of Nitric acid in reaction with sulfur:

• Nitric acid $\left({\mathrm{HNO}}_3\right)$is an oxidizing acid and it can oxidize sulfur into its higher oxidation states $(+4\mathrm{or}+6)$. In this reaction, sulfur is oxidized to sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$.