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 crisis in the Democratic Republic of the Congo person were estimated at 7 m³/person/year in 2014, which indicate only a small level of water resource mobilization (less than 1 percent). Water use per capita in the DRC is considerably lower than in many arid Sahel countries, which experience a physical water scarcity problem. Water is mainly utilized for domestic purposes, comprising 52 percent of total water withdrawals in the DRC. Agriculture accounts for 32 percent of total water withdrawals, followed by industry with 16 percent. Fisheries, hydropower generation and navigation are other important water uses in the DRC, which are typically not included in water use statistics. Water