Reactions Borax

Other reactions. Borax precipitates most of the common metallic cations, not Aik from neutral solutions, and not from ammines of Co, Ni, Cu, Ag, Zn or Cd in aqueous NH3. Rather concentrated solutions of Ae form bulky white precipitates of AeB204, some hydrated. Many other salts give basic salts of the original anion, e.g., sulfate, or of borates. Thorium(4+) and hot B407 " form a borate. The Cr, Fe and AF ions give their hydroxides. Borax and Hg2(N03)2 yield a basic nitrate, and Hg forms its oxide. Tin(II) yields its hydroxide or dismutates into Sn and Sn, but Bi gives a borate. 

Manufacture. Boron trifluoride is prepared by the reaction of a boron-containing material and a fluorine-containing substance in the presence of an acid. The traditional method used borax, fluorspar, and sulfuric acid. 

Chemical Properties. Trimethylpentanediol, with a primary and a secondary hydroxyl group, enters into reactions characteristic of other glycols. It reacts readily with various carboxyUc acids and diacids to form esters, diesters, and polyesters (40). Some organometaUic catalysts have proven satisfactory for these reactions, the most versatile being dibutyltin oxide. Several weak bases such as triethanolamine, potassium acetate, lithium acetate, and borax are effective as stabilizers for the glycol during synthesis (41). 

Inorganic Esters. Boric acid and borax form cycHc esters with poly(vinyl alcohol) (85—100). The reaction is markedly sensitive to pH, boric acid concentration, and the cation-to-boron ratio. An insoluble gel is formed at pH above 4.5—5.0 ... 

When granulated borax or borax-containing Hquors are treated with sulfuric acid, the following reaction ensues ... 

Commercial preparation of sodium perborate tetrahydrate is by reaction of a sodium metaborate solution, from sodium hydroxide and borax pentahydrate, and hydrogen peroxide followed by crystallization of tetrahydrate (95). The tnhydrate and monohydrate can be formed by reversible dehydration of the tetrahydrate. 

Production of borax from the reaction of colemanite and sodium carbonate is carried out in Spain, Italy, and Poland. Turkish production from colemanite has been discontinued in favor of direct production from tincal ore. Sodium borates are produced in Russia from datoHte and in Kazakhstan from szaibelyite. 

U.S. Borax Research Corp., Anaheim, California, markets several borate esters under the trademark BORESTER. These include triethanolamine borate (BORESTER 20), tricresyl borate (m- and p-isomers) (BORESTER 8), and the biborate (4) (BORESTER 7). Whereas the chemical name for (4) is given in Table 1, it is commonly referred to as trihexylene glycol biborate [26545-48-2] and is prepared by the reaction of two moles of boric acid and three moles of hexylene glycol. 

Boron Trichloride. Boron trichloride is prepared on a large scale by the reaction of CI2 and a heated mixture of borax [1303-96-4] ... 

Na2B0402 10H2O, and cmde oil residue (41) in a rotary kiln heated to 1038°C. Borax is fed at the rate of 1360 kg/h and sprayed with 635 kg/h of 17% residue cmde oil. The heated mixture then reacts with CI2 at 760°C in a separate reactor to yield BCl. On a smaller scale, BCl can be prepared by the reaction of CI2 and a mixture of boron oxide [1303-86-2] 2 3 coke, and lampblack in a fluidized bed (42). Other methods for the preparation... 

Sihcon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between sihcon carbide and a variety of compounds at relatively high temperatures. Sodium sihcate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal sihcide. Sihcon carbide decomposes in fused alkahes such as potassium chromate or sodium chromate and in fused borax or cryohte, and reacts with carbon dioxide, hydrogen, ak, and steam. Sihcon carbide, resistant to chlorine below 700°C, reacts to form carbon and sihcon tetrachloride at high temperature. SiC dissociates in molten kon and the sihcon reacts with oxides present in the melt, a reaction of use in the metallurgy of kon and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new sihcon nitride-bonded type exhibits improved resistance to cryohte. 

The diazotization of amino derivatives of six-membered heteroaromatic ring systems, particularly that of aminopyridines and aminopyridine oxides, was studied in detail by Kalatzis and coworkers. Diazotization of 3-aminopyridine and its derivatives is similar to that of aromatic amines because of the formation of rather stable diazonium ions. 2- and 4-aminopyridines were considered to resist diazotization or to form mainly the corresponding hydroxy compounds. However, Kalatzis (1967 a) showed that true diazotization of these compounds proceeds in a similar way to that of the aromatic amines in 0,5-4.0 m hydrochloric, sulfuric, or perchloric acid, by mixing the solutions with aqueous sodium nitrite at 0 °C. However, the rapidly formed diazonium ion is hydrolyzed very easily within a few minutes (hydroxy-de-diazonia-tion). The diazonium ion must be used immediately after formation, e. g., for a diazo coupling reaction, or must be stabilized as the diazoate by prompt neutralization (after 45 s) to pH 10-11 with sodium hydroxide-borax buffer. All isomeric aminopyridine-1-oxides can be diazotized in the usual way (Kalatzis and Mastrokalos, 1977). The diazotization of 5-aminopyrimidines results in a complex ring opening and conversion into other heterocyclic systems (see Nemeryuk et al., 1985). 

Borax is used in laundry detergents and bleaches. It releases hydrogen peroxide when it reacts with water. Hydrogen peroxide acts as a bleach, and its action is aided by the alkaline solution also produced by the reaction. 

The hydrolysis of nitriles to carboxylic acids is one of the best methods for the preparation of these compounds. Nearly all nitriles give the reaction, with either acidic or basic catalysts. Hydrolysis of cyanohydrins, RCH(OH)CN, is usually carried out under acidic conditions, because basic solutions cause competing reversion of the cyanohydrin to the aldehyde and CN . However, cyanohydrins have been hydrolyzed under basic conditions with borax or alkaline borates. ... 

The reaction between MgO and ammonium dihydrogen phosphate (ADP) in aqueous solution yields struvite, MgNH4P04. bHjO, and schertelite, Mg(NH4)2(HP04)2.4H2O, as the main reaction products. Both may be regarded as cementing species. Only minor amounts of MgO are consumed during these reactions as it is present in excess. The reaction is exothermic. Sodium tripolyphosphate (STPP) or borax may be added to retard the reaction. The main course of the reactions may be represented thus ... 

Quartz glass (silica), pyrex (borosilicates) and other household and laboratory glasses (boroaluminosilicates) owe their high chemical resistance to the (tetrahedral) network forming properties of Si, B, P and A1 (cf., the borax and phosphate bead tests in qualitative dry reactions on the salts of numerous metals). 

Figure 4. The rate of isothermal heat release versus reaction time for a 4.4 mm hardboard of groundwood containing 8% of a 50/50 mixture of borax and boric acid. (Reproduced with permission from ref. 10. Copyright 1989 De Gruyter.)...

Very recently, ball milling was also nsed to synthesize sodium borohydride, NaBH, by mechano-chemical reaction of dehydrated borax (Na B O,), MgH and Na COj (at room temperature) according to the following reaction [176]... 

Z.P. Li, N. Morigazaki, B.H. Liu, S. Suda, Preparation of sodium borohydride by the reaction of MgHj with dehydrated borax through ball milling at room temperature , J. Alloys Compd. 349 (2003) 232-236. 

This preparative scheme leads to only 30% yield due to the side reactions between the meto-astatoaniline diazonium salt and astato-phenol, which cannot be eliminated even by continuous extraction of the product with n-heptane (167). All the astatophenols synthesized to date have been identified by either HPLC (99,104) or TLC (160,166,167). Their dissociation constants (KJ have been established from extraction experiments by measuring the relative distribution of compounds between aqueous borax buffer solutions and n-heptane as a function of acidity. On the basis of these derived values, the Hammett a-constants and hence the field (F) and resonance (R) effects have been estimated for these compounds (167) (see Table VI). The field effect for astatine was found to be considerably weaker than that for other halogens the resonance effect was similar to that for iodine (162). 

Boric acid is produced from borax, colemanite, or other inorganic borates by reaction with sulfuric acid or hydrochloric acid, and cooling the solution to proper temperature ... 

Similar reactions occur with many other chlorine-containing compounds, BCI3 being produced (see Boron Trichloride reactions). Anhydrous borax and BCI3 are obtained when it is heated with sodium chloride at 800°C ... 

One of the most efficient methods for oxidation of primary alcohols to either aldehydes or carboxylic acids is the one, commonly known as the Anelli oxidation. This reaction is carried out in a two-phase (CH2Cl2/aq.buffer) system utilizing TEMPO/NaBr as a catalyst and NaOCl as the terminal oxidant The new system described here is an extension of the Anelli oxidation, but surprisingly, does not require the use of any organic solvents and replaces the KBr co-catalyst with the more benign, Na2B40y (Borax). The use of the new cocatalyst reduces the volume of the buffer solution and eliminates completely the need of a reaction solvent. The new system was successfully applied in the industrial synthesis of the 3,3-Dimethylbutanal, which is a key intermediate in the preparation of the new artificial sweetener Neotame. 

Preparation from Borax. Dissolve 12 g of borax in 25 ml of water in a beaker with heating. What is the reaction of the solution to litmus and what is it due to Write the molecular and net-ionic equations of the borax hydrolysis reaction. How can the hydrolysis of borax be facilitated Calculate what amount of a 25% hydrochloric acid solution is needed to prepare boric acid from 12 g of borax. Measure off the calculated amount of acid, and taking a small excess amount, pour the acid into the hot borax solution. Let the solution cool slowly. What substance crystallizes Filter off the crystals on a Buchner funnel, dry them between filter paper sheets, and recrystallize them from hot water, guiding yourself by the table of solubilities. Determine the product yield (in per cent). Keep the prepared boric acid for the following experiments. 

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