Both water and hydrogen peroxide are made up of oxygen and hydrogen but in different proportions. The chemical properties of both compounds differ greatly although they look similar physically. While water is a neutral compound and a necessary ingredient in the biochemical reactions that occur in the body, hydrogen peroxide is a weak acid and a toxic compound in the body. Hydrogen peroxide is denser than water; it is 40% more denser than water. The boiling and the melting point of the compounds also differ.