Sulfur Dioxide SO2

Precursor to sulfuric acid:

Sulfur dioxide is an intermediate in the production of sulfuric acid, being converted to sulfur trioxide, and then to oleum, which is made into sulfuric acid.

As a preservative reducing agent:

Sulfur dioxide is sometimes used as a preservative for dried apricots, dried figs, and other dried fruits, it is also a good reductant.

As a refrigerant:

Being easily condensed and possessing a high heat of evaporation, sulfur dioxide is a candidate material for refrigerants.