Oxidation-reduction magnesium

Thermal Reduction. Magnesium metal can also be formed by the thermal reduction of magnesium oxide with a reactive metal, such as siUcon [7440-21-3] which forms a stable oxide. 

Finely divided zirconium powder is made by bomb reduction of zirconium oxide with magnesium or calcium. The powder is separated by leaching... 

Cerous bromide [14457-87-5] CeBr, and praseodymium bromide [13536-53-3] PrBr, are claimed to be suitable for a molten salt bath used for the reduction of uranium oxide by magnesium (16). PrBr is claimed to be alight filter in a cathode ray tube (17). 

The intensive increase in capacitor production has initiated the development of novel processes for the production of tantalum and niobium capacitor-grade powders, and the successful development of a new method, based on the reduction of tantalum or niobium oxide using magnesium vapors, was recently announced [38]. 

The ease of oxidation of magnesium is important in the commercial manufacture of titanium metal. Titanium, when quite pure, shows great promise as a structural metal, but the economics of production have thus far inhibited its use. One of the processes currently used, the Kroll process, involves the reduction of liquid titanium tetrachloride with molten metallic magnesium ... 

The reaction is carried out under an inert atmosphere in an open crucible at approximately 830°C. Figure 1 shows typical equipment used for direct oxide reduction. Vitrified magnesium oxide ceramic is commonly used as a container material, but tungsten and tantalum can also be used(3). If the latter are used, CaF2 is added to lower the temperature needed to liquify... 

The reaction of magnesium metal with aqueous strong acid, which appears in Figure 4-12. illustrates the fundamental principles of oxidation-reduction. When a piece of magnesium is dropped into a solution of hydrochloric acid, a reaction starts almost Immediately. The metal dissolves, and gas bubbles from the solution. The gas is H2, and analysis of the solution reveals the presence of ions. A list of chemical species before and after the reaction... 

Separating oxidation from reduction makes it possible to verify that electrons are conserved in a redox reaction. Note that the electrons produced in the oxidation of magnesium are consumed in the reduction of hydronium ions. The electrons required for a reduction must come from an oxidation. 

The above reaction shows that the oxychloride decomposes at the sublimation temperature into the volatile tetrachloride and the nonvolatile oxide. Reduction starts as soon as the chloride vapour contacts the molten magnesium, and this exothermic reaction raises the temperature of the reaction mixture. The temperature of the reduction crucible is maintained in the range of 800 to 875 °C. The process is carefully controlled by matching the sublimation rate of zirconium tetrachloride with the reduction rate. The conclusion of the reduction is indicated by a fall in temperature and pressure. 

Alternatively, calcium hydride may be prepared by the reduction of calcium oxide with magnesium in the presence of hydrogen ... 

Many metals are also vulnerable to acids, undergoing an oxidation /reduction reaction that produces the metal ion and hydrogen gas. The balanced equation for the reaction between HCl and magnesium is... 

The reaction of magnesium and oxygen is an example of an oxidation reaction. The combination of an element with oxygen was the traditional way to define an oxidation reaction. This definition of oxidation has been broadened by chemists to include reactions that do not involve oxygen. Our modern definition for oxidation is that oxidation takes place when a substance loses electrons. Anytime oxidation takes place and a substance loses one or more electrons, another substance must gain the electron(s). When a substance gains one or more electrons, the process is known as reduction. Reactions that involve the transfer of one or more electrons always involve both oxidation and reduction. These reactions are known as oxidation-reduction or redox reactions. 

Metallic magnesium is produced by either chemical or electrolytic reduction of its compounds. In chemical reduction, magnesium oxide is obtained from the decomposition of dolomite. Then ferrosilicon, an alloy of iron and silicon, is used to reduce the MgO at about 1200°C. At this temperature, the magnesium produced is immediately vaporized and carried away. The electrolytic method uses seawater as its principal raw material. The first stage is the precipitation of magnesium hydroxide with slaked lime (calcium hydroxide) ... 

Magnesium metal burns in air with an intense white light to form solid magnesium oxide. Red phosphorus reacts with liquid bromine to form liquid phosphorus tribromide. Purple aqueous permanganate ion, MnC>4-, reacts with aqueous Fe2+ ion to yield Fe3+ and pale pink Mn2+. Although these and many thousands of other reactions appear unrelated, all are oxidation-reduction reactions. 

Write a balanced equation for the reduction of boron oxide by magnesium. 

In support of that explanation, X-ray analysis of the catalyst after use indicated the presence of MgO. Hence, the catalytically active phase was finely divided copper in intimate contact with magnesia, quasi as carrier. The same phenomenon was observed with the Zintl-phase alloys of silver and magnesium. Such catalysts were then deliberately prepared by coprecipitation of copper and silver oxides with magnesium hydroxide, followed by dehydration and reduction. Table I shows that these supported catalysts had the same activation energies as those formed by in situ decomposition of copper and silver alloys with magnesium. 

Chelants have been employed in cooling water treatments for many years because of their ability to control calcium, magnesium, iron, etc. Formula-tors have also long used chelants because of buffering, solubilization, and oxidation/reduction control effects. 

The principal commercial methods in use for production of elemental boron are the Moissan reduction of boric oxide with magnesium for 90% amorphous boron and thermal decomposition of boron trichloride in hydrogen for crystalline... 

Elemental boron is produced by the reduction of boron oxide by magnesium to give boron and magnesium oxide. Write a balanced equation for this reaction. 

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