Sulfur dioxide is a chemical compound in the form of gas at room temperature with chemical formula SO2, is. This article by volcanoes and a lot of industrial activity can be produced. Burning oil and coal, due to the presence of sulfur-containing compounds in the production of this gas is associated. Usually because NO2 in the atmosphere causing the reaction of the gas with the water vapor contained in the air, and the formation of sulfuric acid can be. This gas is colorless, toxic, has a mass of molar 64, the 07 g mol in. density 1. the 551 grams per liter, etc., melting point 75. the 5 - degree centigrade, and boiling point 10٫0 - degrees Celsius and is flammable, causing not.