The French use the word chateau for castle but it used to cover both: the Chateau-Gaillard, a fortress of the 12th century; and the manors dating from the 12th to the 18th century, which have no or little defensive capability.he French use the word chateau for castle but it used to cover both: the Chateau-Gaillard, a fortress of the 12th century; and the manors dating from the 12th to the 18th century, which have no or little defensive capability.
Hydrate, any compound containing water in the form of H2O molecules, usually, but not always, with a definite content of water by weight. The best-known hydrates are crystalline solids that lose their fundamental structures upon removal of the bound water.
In many cases, hydrates are coordination compounds. CuSO4â5H2O is actually [Cu(H2O)4]SO4â4H2O; four molecules of water of hydration are coordinated to the copper ion, whereas the fifth water molecule is linked to the sulfate ion, presumably by hydrogen bonding. Similarly, MgSO4â7H2O is actually [Mg(H2O)6]SO4â4H2O.