Calcium tetraborate

CaB407 CALCIUM TETRABORATE 450 Ca2V207 CALCIUM PYROVANADATE 490... 

Figure 11.2. Effect of a second salt (calcium tetraborate) on the foam cell size of FEP. ...

Calcium Tetraborate - It has a chemical formula CaB204 (hydrate form CaB204 4H20) and is a nucleating agent in foaming fluoroplastics, also see Ch. 11. 

Wa.terBa.la.nce Chemicals. Water balance chemicals include muriatic acid, sodium bisulfate, and soda ash for pH control, sodium bicarbonate for alkalinity adjustment, and calcium chloride for hardness adjustment. A recent development is use of buffering agents for pH control. One of these products, sodium tetraborate, hydrolyzes to boric acid and a small amount of orthoborate (50) which provides significantly less buffering than carbonate and cyanurate alkalinity in the recommended pool pH range of 7.2—7.8 even at 100 ppm. 

Either the Mohr titration or the adsorption indicator method may be used for the determination of chlorides in neutral solution by titration with standard 0.1M silver nitrate. If the solution is acid, neutralisation may be effected with chloride-free calcium carbonate, sodium tetraborate, or sodium hydrogencarbonate. Mineral acid may also be removed by neutralising most ofthe acid with ammonia solution and then adding an excess of ammonium acetate. Titration of the neutral solution, prepared with calcium carbonate, by the adsorption indicator method is rendered easier by the addition of 5 mL of 2 per cent dextrin solution this offsets the coagulating effect of the calcium ion. If the solution is basic, it may be neutralised with chloride-free nitric acid, using phenolphthalein as indicator. 

From tamarind seed xyloglucan, carboxymethyl derivatives with different levels of DS were prepared in isopropanol medium [440]. Swelling power, solubihty and tolerance to organic solvents of the derivatives increased with increasing DS. The interaction properties of the unmodified xyloglucan with calcium chloride and sodiiun tetraborate were found to be reversed upon car-boxymethylation. 

Although boron ranks 48th among the elements in abundance, it is not found uncombined. The most common minerals containing boron are the tetraborates of sodium or calcium. Borax, Na2B407 10H2O, is the most important source of boron, and large deposits of borax are found in southern California, from which about three-fourths of the world demand is obtained. 

Pentaborane Diborane Decaborane Sodium borate Boron trifluoride Calcium borate Boron tribromide Boron oxide Total dust Respirable fraction Sodium tetraborate Decahydrate... 

Boron occurs as Tasorite ot kernite (sodium tetraborate tetrahydrate, Nai B4 O7- 4H2 O) and colemanite (calcium borale, Ca2 Be O, 511 O) in California, as sassolite (boric acid, H3 BO31 m Tuscany, Italy, and also locally in Chile, Turkey, and Tibet. See also Colemanite Kernite and Ulexite. 

Boron is the 48th most abundant element by weight in the earth s crust. This number is deceiving because boron ranks approximately 30th in the crust with respect to number of atoms. However, boron is not found in the elemental state in nature, but rather it is usually found as the tetraborate of sodium or calcium. The principal ore is borax, Na2B4O7 10H2O. Large deposits of borax are located in Southern California. It is here that about 75% of the world supply is mined. 

Gather these materials Distilled water (H20) ordinary tap water (H20 with impurities) soap calcium bicarbonate (Ca(HC03)2) magnesium sulfate (MgS04) sodium tetraborate (Na2B407) or potassium carbonate (K2C03) 6 test tubes a test tube rack a test tube holder an alcohol burner a quart jar and an eye dropper. 

Results Distilled water (test tube No. 1) made suds very easily and didn t require many drops of soap solution or much shaking. Tap water (test tube No. 2) made suds easily or else not at all, depending upon what part of the country you live in. The more minerals dissolved in your water, the less easily suds form. The calcium bicarbonate solution (test tube No. 3) made very few suds, and those that it did make disappeared very quickly. The other calcium bicarbonate solution (test tube No. 4) made very good suds after you boiled it and after a white precipitate separated out. The magnesium sulfate solution (test tube No. 5) formed few suds. The other magnesium sulfate solution (test tube No. 6) made goods suds after you added sodium tetraborate or potassium carbonate. 

The principal source of compounds of boron is the complex borate minerals, including borax, sodium tetraborate decahydrate, Na2B407 IOH2O kemite, sodium tetraborate tetrahydrate, NaoB407 4H.20 (which gives borax when water is added) and colemanite, calcium hexaborate pentahydrate, CaoB. O, 51400. The main deposits of these minerals are in California. 

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