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It may be formed by the salt metathesis reaction of potassium chromate and iron(III) nitrate, which gives potassium nitrate as byproduct. 2 Fe(NO 3) 3 + 3 K 2 CrO 4 → Fe 2 (CrO 4)3 + 6 KNO 3. It also can be formed by the oxidation by air of iron and chromium oxides in a basic environment: 4 Fe 2 O 3 + 6 Cr 2 O 3 + 9 O 2 → 4 Fe 2 (CrO 4) 3
Ferric chloride is an alternative name for iron(III) chloride (FeCl 3). The adjective ferrous is used instead for iron(II) salts, containing the cation Fe 2+. The word ferric is derived from the Latin word ferrum, meaning "iron". Although often abbreviated as Fe 3+, that naked ion does not exist
Its importance lies in its ability to mediate electron transfer. In the ferrous state (Fe 2+), iron acts as an electron donor, while in the ferric state (Fe 3+) it acts as an acceptor. Thus, iron plays a vital role in the catalysis of enzymatic reactions that involve electron transfer (reduction and oxidation, redox).
Iron forms various oxide and hydroxide compounds; the most common are iron(II,III) oxide (Fe 3 O 4), and iron(III) oxide (Fe 2 O 3). Iron(II) oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds whose compositions may vary. [12]
When metallic iron (oxidation state 0) is placed in a solution of hydrochloric acid, iron(II) chloride is formed, with release of hydrogen gas, by the reaction Fe 0 + 2 H + → Fe 2+ + H 2. Iron(II) is oxidized by hydrogen peroxide to iron(III), forming a hydroxyl radical and a hydroxide ion in the process. This is the Fenton reaction.
The reflux system in a typical industrial distillation column. Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial [1] and laboratory [2] distillations. It is also used in chemistry to supply energy to reactions over a long period of time.
[3] The hydrogen chromate ion, HCrO 4 −, is a weak acid: HCrO − 4 ⇌ CrO 2− 4 + H +; pK a ≈ 5.9. It is also in equilibrium with the dichromate ion: 2 HCrO − 4 ⇌ Cr 2 O 2− 7 + H 2 O. This equilibrium does not involve a change in hydrogen ion concentration, which would predict that the equilibrium is independent of pH.
In the absence of EDTA or similar chelating agents, ferric ions form insoluble solids and are thus not bioavailable. [1] Together with pentetic acid (DTPA), EDTA is widely used for sequestering metal ions. Otherwise these metal ions catalyze the decomposition of hydrogen peroxide, which is used to bleach pulp in papermaking. Several million ...