Water of crystallization degree of hydration can be critical to the resulting chemical properties. For example, anhydrous RhCl is not soluble in water and is relatively useless in organometallic chemistry whereas RhCl•3HO is versatile. Similarly, hydrated AlCl is a poor Lewis acid and thus inactive as a catalyst for Friedel-Crafts reactions. Samples of AlCl must therefore be protected from atmospheric moisture to preclude the formation of hydrates. Crystals of hydrated copper(II) sulfate consist of [Cu(HO)] centers linked to SO ions. Copper is surrounded by six oxygen atoms, provided by two different sulfate groups and four molecules of water. A fifth water resides elsewhere
Water for injection Water for injection Water for injection is water of extra high quality without significant contamination. A sterile version is used for making solutions that will be given by injection. Before such use other substances generally must be added to make the solution more or less isotonic. It can be given by injection into a vein, muscle, or under the skin. A non-sterile version may be used in manufacturing with sterilization occurring later in the production process. If it is given by injection into a vein without making it more or less isotonic, breakdown of red blood cells may occur. This