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 law in the United States decide the nature of the respective rights of public and private parties arising from the alteration of the hydrology of a watershed. It is important to recognize that there are both private and public 'rights' associated with the water, but that ownership of the water under common law is likened to claiming to "own" sunlight. Water must be legally appropriated before it is 'owned', and regulations on appropriation are typically controlled by government agencies and case laws. Who has domain over water is typically based on who owns the underlying soils, but Local, State and Federal regulations often limit the