Final answer:
SO₂'s colorlessness and high solubility in water are significant because they facilitate its participation in aqueous reactions. Charcoal catalyzes the reaction forming thionyl chloride.
Step-by-step explanation:
The observation that sulfur dioxide (SO₂) is colorless and highly soluble in water indicates that it can be easily incorporated into aqueous reactions without altering the visual properties of the solution. Its solubility also makes it reactive with other substances dissolved in water.
In the reaction between SO₂ and chlorine (Cl₂) to form thionyl chloride (SOCl₂), the role of charcoal is to act as a catalyst. Catalysts increase the rate of chemical reactions without being consumed in the process.
Though the original question mentions SO₂ reacting with Cl₂ to form thionyl chloride, the provided information is about the decomposition of sulfuryl chloride (SO₂Cl₂) into SO₂ and Cl₂, which is a different reaction. Writing chemical equations for such reactions is essential for understanding chemical processes and stoichiometry.