The reaction between sulphur and oxygen is a chemical reaction in which, with gentle heating, sulphur burns in oxygen to produce colorless sulphur dioxide gas. It burns with a pale blue flame.
Sulphur dioxide is soluble in water and has an unpleasant and suffocating smell of burnt matches. Sulphur dioxide can be converted further into sulphur trioxide in the presence of oxygen. According to Purdue University, sulphur dioxide dissolves in water to produce sulphuric acid. Over 50 percent of sulphuric acid produced per year is used to make fertilizers. If heated chlorine passes over heated sulphur, it produces a foul-smelling, orange liquid called disulfur dichloride.