Hydriodic acid is an aqueous solution of hydrogen iodide whose chemical formula is HI. It is formed when hydrogen iodide (colorless gas with a sharp odor) is dissolved in water to form a pale yellow solution, which is strong and highly corrosive.
Due to its acidity and strong reducing ability, hydriodic acid is used as a reducing agent in the production of acetic acid. Acetic acid is used to produce vinegar. Its high level of acidity can kill various types of viruses and germs, making it the ideal substance for sanitizing and disinfecting medical products and tools. Hydriodic acid is not pure hydrogen iodide but simply a mixture containing it.