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The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}} See also [ edit ]
Oxalate (systematic IUPAC name: ethanedioate) is an anion with the chemical formula C 2 O 2− 4. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na 2 C 2 O 4), and several esters such as dimethyl oxalate ((CH 3) 2 C 2 O 4). It is a conjugate base of oxalic acid.
Calcium oxalate crystals are commonly found in lichens, where they occur in two mineral forms: weddellite (CaC 2 O 4 ·(2+x)H 2 O) and whewellite (CaC 2 O 4 ·H 2 O). These crystals can form both on the surface of the lichen as a powdery coating called pruina and within the internal structures of the lichen thallus. The type and distribution of ...
When an oxidizer (Ox) accepts a number z of electrons ( e −) to be converted in its reduced form (Red), the half-reaction is expressed as: Ox + z e − → Red. The reaction quotient (Q r) is the ratio of the chemical activity (a i) of the reduced form (the reductant, a Red) to the activity of the oxidized form (the oxidant, a ox).
It occurs naturally in many foods. Excessive ingestion of oxalic acid or prolonged skin contact can be dangerous. Oxalic acid has much greater acid strength than acetic acid. It is a reducing agent [9] and its conjugate bases hydrogen oxalate (HC 2 O − 4) and oxalate (C 2 O 2− 4) are chelating agents for metal cations.
Oxalate oxidase （Enzyme Commission number EC 1.2.3.4 [2] ）occurs mainly in plants. It can degrade oxalic acid into carbon dioxide and hydrogen peroxide. [3]Oxalate decarboxylase (OXDC，EC 4.1.1.2) is a kind of oxalate degrading enzyme containing Mn 2+, [4] found mainly in fungi or some bacteria.
It contains sodium cations Na + and oxalate anions C 2 O 2− 4. It is a white, crystalline, odorless solid, that decomposes above 290 °C. [2] Sodium oxalate can act as a reducing agent, and it may be used as a primary standard for standardizing potassium permanganate (KMnO 4) solutions. The mineral form of sodium oxalate is natroxalate.
The carbonate oxalates are mixed anion compounds that contain both carbonate (CO 3) and oxalate (C 2 O 4) anions. Most compounds incorporate large trivalent metal ions, such as the rare earth elements. Some carbonate oxalate compounds of variable composition are formed by heating oxalates. [1]