Anhydrous boric acid

Boric oxide, B2O3, is also referred to as anhydrous boric acid. The article of commerce is an amorphous material produced by fusing boric acid in a furnace. The structure of vitreous B2O3 is discussed above. Using a process... 

Boric Oxide. Boric oxide, B203, formula wt 69.62, is the only commercially important oxide. It is also known as diboron trioxide, bone anhydride, or anhydrous boric acid. B203 is normally encountered in the vitreous state. This colodess, glassy solid has a Mohs hardness of 4 and is usually prepared by dehydration of boric acid at elevated temperatures. It is mildly hygroscopic at room temperature, and the commercially available material contains ca 1 wt % moisture as a surface layer of boric acid. The reaction with water ... 

Minerals and compounds sold or used by producers. Includes orthoboric and anhydrous boric acid. 

The facile exchange of boron-carbon with boron-oxygen bonds has been applied to the synthesis of trialkylboroxines from trialkylboranes and anhydrous boric acid (115). 

Boric oxide, also known as anhydrous boric acid, is a hard glassy material, softens at about 325°C, and melts at about 450°C-465°C. It is produced commercially by the fusion of boric acid. Through this procedure, it generally contains up to 0.5% water. It can absorb water and revert back to boric acid however, this normally does not affect its fire retardancy. 

Boric Anhydride. Boron oxide boron trioxide boric oxide boron sesquioxide. B202 mol wt 69.64. B 31.07%, O 63.93%. Improperly called anhydrous boric acid or fused boric acid. Prepn of crystalline form McCulloch, J. Am. Chem. Soc. 59, 2650 (1937). 

Boletic Acid Boracic Acid Borax, Anhydrous Boric Acid Boron Chloride Boron Tribromide Boron Trichloride Bottled Gas... 

Boric oxide, also known as anhydrous boric acid, is produced commercially by calcining boric acid (equation 2) ... 

Boric oxide, B2O3, the simplest and only commercially important oxide of boron, exists primarily as an amorphous glass that has a 3-D arrangement of three-coordinate boron centers (BO3) that share oxygen atoms [9]. It finds application mainly in glass and ceramics. It is water soluble, although it dissolves relatively slowly in an exothermic reaction with water. It is often referred to as anhydrous boric acid, as it converts to and behaves like boric acid on contact with water. 

Boric oxide (anhydrous boric acid) Boric acid... 

Lead borate moaohydrate [14720-53-7] (lead metaborate), Pb(B02)2 H20, mol wt 310.82, d = 5.6g/cm (anhydrous) is a white crystalline powder. The metaborate loses water of crystallization at 160°C and melts at 500°C. It is iasoluble ia water and alkaHes, but readily soluble ia nitric and hot acetic acid. Lead metaborate may be produced by a fusion of boric acid with lead carbonate or litharge. It also may be formed as a precipitate when a concentrated solution of lead nitrate is mixed with an excess of borax. The oxides of lead and boron are miscible and form clear lead-borate glasses in the range of 21 to 73 mol % PbO. 

Lithium Borates. Lithium metaborate [13453-69-5], LLBO2 2H20, is prepared from reaction of lithium hydroxide and boric acid. It is used as the fluxing agent for the matrix for x-ray fluorescence analytical techniques and in specialty glasses and enamels. The anhydrous salt melts at 847°C. 

The tertiary metal phosphates are of the general formula MPO where M is B, Al, Ga, Fe, Mn, etc. The metal—oxygen bonds of these materials have considerable covalent character. The anhydrous salts are continuous three-dimensional networks analogous to the various polymorphic forms of siHca. Of limited commercial interest are the alurninum, boron, and iron phosphates. Boron phosphate [13308-51 -5] BPO, is produced by heating the reaction product of boric acid and phosphoric acid or by a dding H BO to H PO at room temperature, foUowed by crystallization from a solution containing >48% P205- Boron phosphate has limited use as a catalyst support, in ceramics, and in refractories. 

Decahydrate, Pentahydrate, and Anhydrous Borax and Bulk Calcium Borates. The bulk borate products, borax decahydrate and pentahydrate, anhydrous borax, boric acid and oxide, and upgraded colemanite and ulexite, account in both toimage and monetary terms for over 99% of sales of the boron primary products industry (6). Economic considerations for all these products are highly interrelated, and most production and trade statistics do not distinguish the various products. 

In 1986, Turkey produced nearly one million metric tons of mineral concentrate, whereas production of refined borate chemicals was 89,500 metric tons. Annual production capacities of chemicals at Eskiseher were pentahydrate borax, 160,000 t anhydrous borax, 60,000 t and decahydrate borax, 17,000 t. Capacities at Bandermes were decahydrate borax, 55,000 t boric acid, 33,000 t and sodium perborate, 64,000 t (103). 

Anhydrous metal borates may be prepared by heating the hydrated salts to 300—500°C, or by direct fusion of the metal oxide with boric acid or B2O2. Many binary and tertiary anhydrous systems containing B2O2 form vitreous phases over certain ranges of composition (145). 

B. Standardisation against sodium tetraborate. The advantages of sodium tetraborate decahydrate (borax) are (i) it has a large relative molecular mass, 381.44 (that of anhydrous sodium carbonate is 106.00) (ii) it is easily and economically purified by recrystallisation (iii) heating to constant weight is not required (iv) it is practically non-hygroscopic and (v) a sharp end point can be obtained with methyl red at room temperatures, since this indicator is not affected by the very weak boric acid. 

Potassium bisulphate and anhydrous boric or oxalic acid are also used (acrolein from glycerol, pyruvic acid from tartaric acid). Tschugaev s xanthate method belongs to this class of reactions also. 

Materials Required Salbutamol sulphate 50 mg solution of an equimolar mixture of anhydrous sodium carbonate and potassium carbonate (3% w/v in DW) 5.0 ml Solution of curcumin (0.125% w/v in glacial acetic acid) 3.0 ml mixture of H2S04 and glacial CH3COOH (5 ml 5 ml) 3.0 ml ethanol (96%) 100 ml solution of boric acid (dissolve 5 g of boric acid in a mixture of 20 ml DW and 20 ml absolute ethanol and dilute to 250 ml with absolute ethanol) 100 ml. 

Heating with metal oxides at elevated temperatures produces anhydrous borates. Reactions with halogens in the presence of carbon at temperatures above 500°C give boron trdialides. Heating a mixture of boric acid, ammonia and calcium phosphate in an electric furnace produces boron nitride. 

To prepare boron trifluoride, mix 50 g of potassium fluoborate and 9 g of boric acid anhydride in flask 3, and pour 25 ml of anhydrous sulphuric acid into the mixture. Prepare the anhydrous sulphuric acid by adding the relevant amount of 65 % oleum to a 96 % sulphuric acid solution carefully, wear eye protection ). 

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