A run-through of the electrolysis of water In the electrolysis of water, since de-ionized water does not conduct electricity, electrolysis can not be carried out. In the electrolysis experiment, sodium hydroxide is usually added to water. It is said to be electrolyte which water is added to solutions due to having the property that this electricity is passed through. The action in which electricity flows by means of the electrolysis of water means that electrons flow out from the negative side of the battery, but these electrons generate hydrogen by reacting with water due to the electrode (a cathode) being immersed in water. When this hydrogen is kept in a test tube, if it gets near heat, it explodes with squeaky sounds. The following chemical formula is as follows in this chemical reaction. In another electrode (an anode), the reaction occurs as in the expression below, and results in the generation of water and oxygen. The generated electron is passed to an anode, and it flows to the positive pole of the battery through an electric wire. When a burning stick is put close to oxygen stored in the test tube, it flares up into flames. The equation with these two reaction expression added represents the electrolysis of water, and the right and left sides of the equation disappear. Thus, hydrogen and oxygen come out from water as indicated in the equation below.       Process of generating electric power is said to be the reverse of the electrolysis of water, but...   Yes indeed, it is the reverse of electrolysis !