Potassium availability

Niwas, J.M. and Dissanayake, C.B. 1987. Rocks as fertilizers preliminary studies on potassium availability of some common rocks of Sri Lanka. Applied Geochemistry 2 243-246. 

Eno, C.F. and Reuszer, H.W., 1955. Potassium availability from biotite, muscovite, greensand and microcline as determined by growth of Aspergillus niger. Soil Sci., 80 199— 209. 

If only 100 ml. separating-funnels are available, the distillate must be divided into two portions and each extracted with ether as described, the final ether extracts being united for drying with potassium hydroxide. 

Then, while the diazonium solution is standing in ice-water, dissolve 55 g. of powdered copper sulphate (CuS04,5Ha0) in 200 ml. of water contained in a 1500 ml. flat-bottomed flask, for which a steam-distillation fitting is available for subsequent use. Place a thermometer in the copper sulphate solution and warm the latter to 60-65 . Now cautiously add a solution of 60 g. of powdered potassium cyanide in too ml. of water to the copper... 

Metallic potassium is available commercially for about 40/lb in small quantities. 

Several methods are available for producing thorium metal it can be obtained by reducing thorium oxide with calcium, by electrolysis of anhydrous thorium chloride in a fused mixture of sodium and potassium chlorides, by calcium reduction of thorium tetrachloride mixed with... 

To a solution of 0.5D mol of KO-tert.-C Hg (uncomplexed base, commercially available) and 180 ml of dry THF was added at room temperature 0.25 mol of the Mannich product. A weakly exothermic reaction took place. The mixture was heated in a bath at 50°C and the THF started to reflux (occasional cooling in an ice-water bath may be necessary). When the refluxing had ceased, the mixture was heated for 30 min in a bath at 70°C, then cooled to room temperature and 300 ml of redistilled, dry pentane were added. The precipitate of potassium raethoxide and... 

Note 3. This compound is commercially available as a 55% aqueous solution. It can be isolated by saturating the solution with anhydrous potassium carbonate The upper layer is dried over a small amount of potassium carbonate and subsequently distilled b.p. 40 C/35 mmHg. 

The legal basis for the sale of fertilizers throughout the world is laboratory evaluation of content as available nitrogen, phosphorus, and potassium. By convention, numerical expression of the available nutrient content of a fertilizer is by three successive numbers that represent the percent available of N, P20, and K O, respectively. Thus, for example, a 20—10—5 fertilizer contains available nitrogen in the amount of 20% by weight of N, available phosphoms in amount equivalent to 10% of P2O5, and available potassium in amount equivalent to 5% K O. The numerical expression of these three numbers is commonly referred to as the analysis or grade of the fertilizer. Accepted procedures for laboratory analysis are fixed by laws that vary somewhat from country to country. 

Manufacture. Potassium biduoride is produced from potassium hydroxide or potassium carbonate and hydroduoric acid. The concentrated solution is cooled and allowed to crystallize. The crystals are separated centtifugaHy and dried. The commercial product consists typically of 99.7% KHF2 and 0.2% KF. Potassium biduoride is available in the United States in 180-kg dmms at 4.04/kg (1992). 

Lynestrenol is the des-3-oxo derivative of norethindrone (28). It has been prepared through a similar synthetic pathway as aHylestrenol (37) (52), ie, addition of potassium acetyUde, rather than aHyl magnesium bromide, affords lynestrenol (73). Lynestrenol is also available from norethindrone (28). Reduction of the 3-keto group is accompHshed by treating norethindrone (28) with sodium borohydride in the presence of trifluoro- or trichloroacetic acid... 

Potassium, Pubidium, and Cesium idjdrides. Although all the other alkah metal hydrides have been synthesized and some of the properties measured, only potassium hydride [7693-26-7] is commercially available. KH is manufactured in small amounts and sold as a mineral oil dispersion. It is a stronger base than NaH and is used to make the strong reducing agent KBH(C2H )2 and the super bases RNHK and ROK (6). 

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