The chemical formula KOH stands for potassium hydroxide. The first letter, K, is the symbol for the element potassium; the next letter, O, stands for oxygen; and the letter H stands for hydrogen. One oxygen atom bonded to a single hydrogen atom is a hydroxide ion.
KOH is a compound in which each molecule is made from one potassium ion and one hydroxide ion. It is formed by reacting impure potassium with sodium hydroxide. Like many ionic compounds, it is soluble in water and separates into its constituent K(+1) and OH(-1) ions in solution. This makes it a reactive base. The compound is hygroscopic, which means that it absorbs water easily. Because of this, it is used as a drying agent in laboratories.