Carbon oxidation/reduction reactions

The feasibility of performing the water-carbon oxidation-reduction reaction in combination with the C02 absorption by CaO in a single reactor has been confirmed in experiments.1112 The underlying concept of the HyPr-RING process involves two reactors a main... 

Although essentially inert m acid-base reactions alkanes do participate m oxidation-reduction reactions as the compound that undergoes oxidation Burning m air (combus tion) IS the best known and most important example Combustion of hydrocarbons is exothermic and gives carbon dioxide and water as the products... 

The ready reversibility of this reaction is essential to the role that qumones play in cellular respiration the process by which an organism uses molecular oxygen to convert Its food to carbon dioxide water and energy Electrons are not transferred directly from the substrate molecule to oxygen but instead are transferred by way of an electron trans port chain involving a succession of oxidation-reduction reactions A key component of this electron transport chain is the substance known as ubiquinone or coenzyme Q... 

Refining Processes. AH the reduction processes yield an impure metal containing some of the minor elements present in the concentrate, eg, cadmium in 2inc, or some elements introduced during the smelting process, eg, carbon in pig iron. These impurities must be removed from the cmde metal in order to meet specifications for use. Refining operations may be classified according to the kind of phases involved in the process, ie, separation of a vapor from a Hquid or soHd, separation of a soHd from a Hquid, or transfer between two Hquid phases. In addition, they may be characterized by whether or not they involve oxidation—reduction reactions. 

Verify that reaction (23) is an oxidation-reduction reaction and that the oxidation number change of carbon is balanced by the oxidation number change of the sulfur. 

N204 also forms expl mixts with incompletely halogenated hydrocarbons, NGu, carbon disulfide, etc (Ref 33). The effect of spontaneous decompn by oxidation-reduction reactions when N204 is mixed with a number of fuels (hydrazine, gasoline, liq paraffin, etc) has resulted in its extensive use in liq propint rocket engines (Refs 12, 22, 27 35)... 

In Part 2 of this book, we shall be directly concerned with organic reactions and their mechanisms. The reactions have been classified into 10 chapters, based primarily on reaction type substitutions, additions to multiple bonds, eliminations, rearrangements, and oxidation-reduction reactions. Five chapters are devoted to substitutions these are classified on the basis of mechanism as well as substrate. Chapters 10 and 13 include nucleophilic substitutions at aliphatic and aromatic substrates, respectively, Chapters 12 and 11 deal with electrophilic substitutions at aliphatic and aromatic substrates, respectively. All free-radical substitutions are discussed in Chapter 14. Additions to multiple bonds are classified not according to mechanism, but according to the type of multiple bond. Additions to carbon-carbon multiple bonds are dealt with in Chapter 15 additions to other multiple bonds in Chapter 16. One chapter is devoted to each of the three remaining reaction types Chapter 17, eliminations Chapter 18, rearrangements Chapter 19, oxidation-reduction reactions. This last chapter covers only those oxidation-reduction reactions that could not be conveniently treated in any of the other categories (except for oxidative eliminations). 

Electron-transfer reactions occur all around us. Objects made of iron become coated with mst when they are exposed to moist air. Animals obtain energy from the reaction of carbohydrates with oxygen to form carbon dioxide and water. Turning on a flashlight generates a current of electricity from a chemical reaction in the batteries. In an aluminum refinery, huge quantities of electricity drive the conversion of aluminum oxide into aluminum metal. These different chemical processes share one common feature Each is an oxidation-reduction reaction, commonly called a redox reaction, in which electrons are transferred from one chemical species to another. 

Carbon is a reducing agent the oxidised forms of carbon are carbon oxides. The dangerous reactions of these will therefore mainly be oxidation-reduction reactions. 

Silicon is generally considered to be a congener of carbon and this is also reflected in the evolution of silicon as a reducing agent for metal oxides. Silicon forms a fairly stable solid oxide silica or silicon dioxide (Si02) and also a stable gaseous oxide silicon monoxide (SiO), both of which can be useful in oxide reduction reactions. 

The principal abiotic processes affecting americium in water is the precipitation and complex formation. In natural waters, americium solubility is limited by the formation of hydroxyl-carbonate (AmOHC03) precipitates. Solubility is unaffected by redox condition. Increased solubility at higher temperatures may be relevant in the environment of radionuclide repositories. In environmental waters, americium occurs in the +3 oxidation state oxidation-reduction reactions are not significant (Toran 1994). 

It is convenient to divide organic chemical reactions between acid-base and oxidation-reduction reactions as in inorganic chemistry. In acid-base reactions the oxidation states of carbon do not change, e.g. in hydrolysis, where reaction is, for example,... 

CH3CO.OR + H20 - CH3COOH + ROH In oxidation-reduction reactions the oxidation states of carbon change, for example, CH3COOH + H2 - CH3CHO + h2o... 

In addition to oxidation-reduction reactions occurring under various conditions, increased carbon dioxide will also affect soil pH. Carbon dioxide... 

Carbon oxidation produces CO, which reduces the solid iron oxide to hqihd iron. This reaction is strongly exothermic, and this supplies the heat necessary to heat the reactor contents above the melting point of iron metal. Iron ore also contains sihcate slag, and this melts along with the Fe to form a second hquid phase. The oxide reduction reaction step is especially interesting because it involves a gas reacting with a solid to form a Hquid and another gas. 

Not all biological oxidation-reduction reactions involve carbon. For example, in the conversion of molecular nitrogen to ammonia, 6H1 + 6e + N2 2NH3, the nitrogen atoms are reduced. 

We can now construct a balance sheet for glycolysis to account for (1) the fate of the carbon skeleton of glucose, (2) the input of P, and ADP and the output of ATP, and (3) the pathway of electrons in the oxidation-reduction reactions. The left-hand side of the following equation shows all the inputs of ATP, NAD+, ADP, and Pj (consult Fig. 14-2), and the right-hand side shows all the outputs (keep in mind that each molecule of glucose yields two molecules of pyruvate) ... 

Combustion is an oxidation-reduction reaction between a nonmetallic material and molecular oxygen. Combustion reactions are characteristically exothermic (energy releasing). A violent combustion reaction is the formation of water from hydrogen and oxygen. As discussed in Section 9.5, the energy from this reaction is used to power rockets into space. More common examples of combustion include the burning of wood and fossil fuels. The combustion of these and other carbon-based chemicals forms carbon dioxide and water. Consider, for example, the combustion of methane, the major component of natural gas ... 

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