Boron sulfur oxides

Thus the hydride is a very efficient carrier of hydrogen. Upon heating, calcium reacts with boron, sulfur, carbon, and phosphoms to form the corresponding binary compounds and with carbon dioxide to form calcium carbide [73-20-7J, CaC2, and calcium oxide [1305-78-8] CaO. 

In finely divided form, hafnium is pyrophoric, igniting in air spontaneously. However, bulk metal reacts slowly in oxygen or air above 400°C. The rate of oxidation increases with temperature. The product is hafnium dioxide, Hf02. It combines with nitrogen, carbon, boron, sulfur and silicon at very high temperatures to form hafnium nitride HfN, hafnium boride HfB, hafnium sulfide HfSi2, respectively. Nitride formation occurs at 900°C. 

Most borides are inert toward nonoxidizing acids, although Bc2B and MgB2 react with aqueous acids to form boron hydrides. Oxidizing acids such as nitric or hot sulfuric dissolve most borides. Hot aUcahne salt melts and fused alkali peroxides also dissolve borides to form the more stable borates. Borides are generally resistant to oxidation in dry air due to the formation of a protective oxide layer. Many borides do not oxidize in air below 1000 1400 °C. 

By the mid-1960s, multiple concerns arose about the use of boron and fluorine. (1) Boron oxide is a costly batch ingredient and up to 15% of this ingredient in a given melt can volatilize. (2) Fluorine presents a similar problem [4]. (3) The atmospheric temperature above the glass melt in most E-glass production furnaces is between 1400 and 1500°C and the exhaust can react at these temperatures with potassium, sodium and sulfur oxides to form... 

By itself not particularly strong or durable, aluminum in combination with other metals becomes one of the most versatile materials available. It does take vast amounts of electrical energy to manufacture, however, and presently this involves the production of both carbon dioxide and the sulfur oxides. Alums are astringents and the sources of beautiful crystals. Alumina, the oxide, comes in a variety of polymorphs used as various abrasives and in beautiful, gem-quality minerals. It is also the product of the extremely exothermic thermite reaction. Boron Neutron Capture Therapy (BNCT) offers a potential treatment against brain tumors and other difficult-to-treat carcinomas of the head and neck. Gallium, indium, and thallium compounds do not have many applications. 

Nitric oxide Aluminum, BaO, boron, carbon disulflde, chromium, many chlorinated hydrocarbons, fluorine, hydrocarbons, ozone, phosphine, phosphorus, hydrazine, acetic anhydride, ammonia, chloroform, Fe, K, Mg, Mn, Na, sulfur... 

Thousands of compounds of the actinide elements have been prepared, and the properties of some of the important binary compounds are summarized in Table 8 (13,17,18,22). The binary compounds with carbon, boron, nitrogen, siUcon, and sulfur are not included these are of interest, however, because of their stabiUty at high temperatures. A large number of ternary compounds, including numerous oxyhaUdes, and more compHcated compounds have been synthesized and characterized. These include many intermediate (nonstoichiometric) oxides, and besides the nitrates, sulfates, peroxides, and carbonates, compounds such as phosphates, arsenates, cyanides, cyanates, thiocyanates, selenocyanates, sulfites, selenates, selenites, teUurates, tellurites, selenides, and teUurides. 

Cmde diketene obtained from the dimeriza tion of ketene is dark brown and contains up to 10% higher ketene oligomers but can be used without further purification. In the cmde form, however, diketene has only limited stabHity. Therefore, especiaHy if it has to be stored for some time, the cmde diketene is distiHed to > 99.5% purity (124). The tarry distiHation residue, containing trike ten e (5) and other oligomers, tends to undergo violent Spontaneous decomposition and is neutralized immediately with water or a low alcohol. Ultrapure diketene (99.99%) can be obtained by crystallization (125,126). Diketene can be stabHized to some extent with agents such as alcohols and even smaH quantities of water [7732-18-5] (127), phenols, boron oxides, sulfur [7704-34-9] (128) and sulfate salts, eg, anhydrous copper sulfate [7758-98-7]. 

Other THF polymerization processes that have been disclosed in papers and patents, but which do not appear to be in commercial use in the 1990s, include catalysis by boron trifluoride complexes in combination with other cocatalysts (241—245), modified montmorrillonite clay (246—248) or modified metal oxide composites (249), rare-earth catalysts (250), triflate salts (164), and sulfuric acid or Aiming sulfuric acid with cocatalysts (237,251—255). 

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