Concentrated sulfuric acid is an oxidizing agent.
Reason: This is because of the concentrated sulfuric acid in thermal decomposition producing nascent oxygen.
Reaction: H2SO4 → H2SO4 + SO2
Concentrated sulfuric acid is a stable acid.
Reason: It has a high boiling point of about 338˚C. This concentrated sulfuric acid material is used to prepare volatile acids such as nitric acid, hydrochloric acid from its salts by double decomposition.
Reaction: H2SO4 + NaCl → NaHSO4 + HCl