Final answer:
The student's chemistry question deals with the reaction of sulfurous acid and barium hydroxide. This is likely a chemical reaction forming an insoluble sulfate or sulfite salt and water, as barium often forms insoluble sulfates when reacting with sulfate-containing compounds.
Step-by-step explanation:
The reaction in question involves sulfurous acid reacting with barium hydroxide, which is a chemical reaction of an acid with a base. In chemistry, such reactions often produce a salt and water, and sometimes a gas. Given the examples of reactions provided, we can deduce that barium, a group 2 element, often forms insoluble sulfates like BaSO4 when reacting with sulfate-containing compounds. Although the provided examples all involve sulfuric acid (H2SO4), the reaction of sulfurous acid with barium hydroxide would likely form a barium salt (likely barium sulfite, BaSO3) and water.
Barium chloride reacting with sulfuric acid to form barium sulfate and hydrochloric acid (BaCl2 + H2SO4 → BaSO4 + 2HCl) serves as a close comparison, highlighting that barium sulfate is insoluble in water, which could be important to the reaction we're considering. The reactivity series also tells us that sulfates and chlorides of barium have similar precipitation reactions when combined with sulfuric acid.
It's also important to note that sulfuric acid is a diprotic acid, meaning it can donate two protons (H+ ions), forming both sulfates and hydrogen sulfates. In a similar but simpler fashion, sulfurous acid (a different acid from sulfuric acid) would be expected to react with barium hydroxide to form a sulfate or sulfite compound, depending on the reaction conditions.