The molecular formula Ca(HSO3)2 is that of calcium bisulphite. It has a molecular mass of 202.22 grams per mole. Calcium bisulphite is also referred to as calcium hydrogen sulfite and is an inorganic salt formed by a positively charged calcium ion and a negatively charged bisulphite ion.
When sulfurous acid reacts with lime, it forms calcium bisulphite. At room temperature, calcium bisulfite is a yellow liquid with a strong smell of sulfur dioxide.
Calcium bisulfite is used as a food preservative and as a reducing agent in chemical reactions. It behaves as a weak acid in aqueous solutions. It is also used in the paper manufacturing industry.