Hydroiodic acid is a strong acid formed when iodine dissolves in water. Its chemical formula is HI, indicating it consists of hydrogen and iodine. This colorless liquid is highly corrosive and can release harmful fumes, making it important to handle with care. In laboratories, hydroiodic acid is often used as a reagent in organic synthesis and to produce iodine compounds. It can also be utilized in the preparation of iodides, which are important in various chemical reactions and applications, including pharmaceuticals and photography.