User:InterstellarGamer12321/Niobium compounds
From Wikipedia, the free encyclopedia
In many ways, niobium is similar to tantalum and zirconium. It reacts with most nonmetals at high temperatures; with fluorine at room temperature; with chlorine at 150 °C and hydrogen at 200 °C; and with nitrogen at 400 °C, with products that are frequently interstitial and nonstoichiometric.[1] The metal begins to oxidize in air at 200 °C.[2] It resists corrosion by fused alkalis and by acids, including aqua regia, hydrochloric, sulfuric, nitric and phosphoric acids.[1] Niobium is attacked by hydrofluoric acid and hydrofluoric/nitric acid mixtures.
Although niobium exhibits all of the formal oxidation states from +5 to −1, the most common compounds have niobium in the +5 state.[1] Characteristically, compounds in oxidation states less than 5+ display Nb–Nb bonding. In aqueous solutions, niobium only exhibit the +5 oxidation state. It is also readily prone to hydrolysis and is barely soluble in dilute solutions of hydrochloric, sulfuric, nitric and phosphoric acids due to the precipitation of hydrous Nb oxide.[3] Nb(V) is also slightly soluble in alkaline media due to the formation of soluble polyoxoniobate species.[4][5]