Oleum is\

Question

Oleum is\

Professor PC Thomas Classes · Answer

(c) : Pyrosulphuric acid or oleum (+6) is $\mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{7}$ which is obtained by dissolving $\mathrm{SO}_{3}$ and is called fuming sulphuric acid.\