Potassium Iodide 

colorless monoclinic crystal or white crystalline powder, soluble in water, dilute acid and ethylene diamine, ethanolamine and potassium iodide solution; Slightly soluble in liquid sulphur dioxide and ammonia; Insoluble in alcohol and ammonia. In alkaline medium, potassium iodate, hypochlorous acid, etc can be chlorine gas stronger antioxidant for potassium periodate oxidation.