Answer
See answer below.
Work Step by Step
Sulfurous acid decomposes into water and sulfur dioxide.
Reaction: $Na_2SO_3(aq)+2\ CH_3CO_2H(aq)\rightarrow 2\ NaCH_3CO_2(aq)+H_2O(l)+ SO_2(g)$
Reactants: Sodium sulfite, acetic acid.
Products: Sodium acetate, water, sulfur dioxide.