The Importance of a Pure Water

In general terms, water is called pure when it is clear and free from insoluble particles held in suspension. Water is usually purified by distillation because the solid substances in solution are not transformed into vapors. For certain physical and chemical researches however, it is necessary to have perfectly pure water. A solution of potassium permanganate is added to distilled water until the whole is a light rose colour. By this means the organic matter in the water is destroyed, converted into gases, or non-volatile substances.