8KI + 9H2SO4 4I2 + H2S + 4H2O + 8KHSO4
Potassium iodide react with sulfuric acid to produce iodine, hydrogen sulfide, water and potassium bisulfate. Potassium iodide - solid. Sulfuric acid - concentrated solution. This reaction takes place at a temperature of 30-50°C.