H2SO4\mathrm{H}_{2} \mathrm{SO}_{4}H2SO4
H2 S2O7\mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{7}H2 S2O7
SO42−\mathrm{SO}_{4}^{2-}SO42−
H3O+\mathrm{H}_{3} \mathrm{O}^{+}H3O+