what happens when iron reacts with oxygen and water
Rust
title: Anaerobic corrosion text: precipitation of the slightly soluble ferrous hydroxide (Fe(OH)). This finally leads to the global reaction of the anaerobic corrosion of iron in water: Under anaerobic conditions, the ferrous hydroxide (Fe(OH) ) can be oxidized by the protons of water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction: The well crystallized magnetite (FeO) is thermodynamically more stable than the ferrous hydroxide (Fe(OH) ). This process also occurs during the anaerobic corrosion of iron and steel in oxygen-free groundwater and in reducing soils below the water table. Anaerobic corrosion Hydrogen corrosion is a form of metal title: Hydrogen text: of water concomitantly reduced in molecular hydrogen (). The anaerobic corrosion of iron leads first to the formation of ferrous hydroxide (green rust) and can be described by the following reaction: In its turn, under anaerobic conditions, the ferrous hydroxide () can be oxidized by the protons of water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction: The well crystallized magnetite () is thermodynamically more stable than the ferrous hydroxide (). This process occurs during the anaerobic corrosion of iron and steel in oxygen-free groundwater and in reducing soils below the water table. In title: Properties of water text: One example of an alkali metal reacting with water is: Some other reactive metals, such as aluminum and beryllium, are oxidized by water as well, but their oxides adhere to the metal and form a passive protective layer. Note that the rusting of iron is a reaction between iron and oxygen that is dissolved in water, not between iron and water. Water can be oxidized to emit oxygen gas, but very few oxidants react with water even if their reduction potential is greater than the potential of . Almost all such reactions require a catalyst. An example of the oxidation title: Iron(II) hydroxide text: Iron(II) hydroxide Iron(II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH). It is produced when iron(II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidized solid is sometimes known as "green rust". Iron(II) hydroxide is poorly soluble in water (1.43 × 10 g/L), or 1.59 × 10 mol/L. It precipitates from the reaction of iron(II) and hydroxide salts: If the solution is not deoxygenated and the iron reduced, the precipitate can vary in color starting title: Electrochemistry text: to occur the metal has to be in contact with oxygen and water, although chemical reactions for this process are relatively complex and not all of them are completely understood. It is believed the causes are the following: Electron transfer (reduction-oxidation) Iron corrosion takes place in an acid medium; H ions come from reaction between carbon dioxide in the atmosphere and water, forming carbonic acid. Fe ions oxidizes, following this equation: Iron(III) oxide hydrate is known as rust. The concentration of water associated with iron oxide varies, thus the chemical formula is represented by <chem>2Fe2O3.\mathit{x}H2O</chem>. An electric circuit is formed