Question

S-SO2-H2SO4-Na2SO3-SO2-CaSO3​

Answer 1

S + O2 = SO2

SO2 + 2H2O + Br → H2SO4 + 2HBr

H2SO4 + 2NaI → Na2SO3 + I2 + H2O

Na2SO3 →t→ Na2O + SO2

CaO + SO2 = CaSO3

Answer 2

It seems like you've provided a sequence of chemical compounds or elements. Please clarify what you would like to know or discuss about these compounds. Are you interested in their chemical properties, reactions, or something else? Feel free to provide more details, and I'll be happy to assist you further.