Question

все возможные реакции с SO3

Answer 1

SO3 + H2O = H2SO4

SO3 + Na2O = Na2SO4

SO3 + 2NaOH = Na2SO4 + H2O

Answer 2

2SO3+C-->2SO2+CO2
SO3+CaO-->CaSO4
SO3+NaOH-->NaHSO4