When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Iron(III) oxide - Wikipedia

    en.wikipedia.org/wiki/Iron(III)_oxide

    Iron(III) oxide is a product of the oxidation of iron. It can be prepared in the laboratory by electrolyzing a solution of sodium bicarbonate, an inert electrolyte, with an iron anode: 4 Fe + 3 O 2 + 2 H 2 O → 4 FeO(OH) The resulting hydrated iron(III) oxide, written here as FeO(OH), dehydrates around 200 °C. [18] [19] 2 FeO(OH) → Fe 2 O 3 ...

  3. Porosity - Wikipedia

    en.wikipedia.org/wiki/Porosity

    Connected porosity is more easily measured through the volume of gas or liquid that can flow into the rock, whereas fluids cannot access unconnected pores. Porosity is the ratio of pore volume to its total volume. Porosity is controlled by: rock type, pore distribution, cementation, diagenetic history and composition. Porosity is not controlled ...

  4. Iron (II,III) oxide - Wikipedia

    en.wikipedia.org/wiki/Iron(II,III)_oxide

    Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe 3 O 4. It occurs in nature as the mineral magnetite . It is one of a number of iron oxides , the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe 2 O 3 ) which also occurs naturally as the mineral hematite .

  5. Ferrihydrite - Wikipedia

    en.wikipedia.org/wiki/Ferrihydrite

    It can be precipitated directly from oxygenated iron-rich aqueous solutions, or by bacteria either as a result of a metabolic activity or passive sorption of dissolved iron followed by nucleation reactions. [9] Ferrihydrite also occurs in the core of the ferritin protein from many living organisms, for the purpose of intra-cellular iron storage ...

  6. Iron oxide - Wikipedia

    en.wikipedia.org/wiki/Iron_oxide

    Iron oxides feature as ferrous or ferric or both. They adopt octahedral or tetrahedral coordination geometry. Only a few oxides are significant at the earth's surface, particularly wüstite, magnetite, and hematite. Oxides of Fe II. FeO: iron(II) oxide, wüstite; Mixed oxides of Fe II and Fe III. Fe 3 O 4: Iron(II,III) oxide, magnetite; Fe 4 O ...

  7. Darken's equations - Wikipedia

    en.wikipedia.org/wiki/Darken's_equations

    Darken’s equations can be applied to almost any scenario involving the diffusion of two different components that have different diffusion coefficients. This holds true except in situations where there is an accompanying volume change in the material because this violates one of Darken’s critical assumptions that atomic volume is constant.

  8. Iron compounds - Wikipedia

    en.wikipedia.org/wiki/Iron_compounds

    The iron compounds produced on the largest scale in industry are iron(II) sulfate (FeSO 4 ·7H 2 O) and iron(III) chloride (FeCl 3). The former is one of the most readily available sources of iron(II), but is less stable to aerial oxidation than Mohr's salt ((NH 4) 2 Fe(SO 4) 2 ·6H 2 O). Iron(II) compounds tend to be oxidized to iron(III ...

  9. Poromechanics - Wikipedia

    en.wikipedia.org/wiki/Poromechanics

    The Eulerian porosity, (), which measures the porosity with respect to the current or deformed configuration. Specifically, if d V t {\displaystyle \mathrm {d} V_{t}} represents an infinitesimal volume in the deformed material body, then the pore volume is calculated from n ( x ) d V t {\displaystyle n(\mathbf {x} )\mathrm {d} V_{t}} .