Potassium sulphate

CH2 CH CH0. a colourless, volatile liquid, with characteristic odour. The vapour is poisonous, and intensely irritating to eyes and nose b.p. 53"C. It is prepared by the distillation of a mixture of glycerin, potassium sulphate and potassium hydrogen sulphate. It is manufactured by direct oxidation of propene or cross-condensation of ethanal with meth-anal. 

Ammonium cyanate, because of its instability in solution, is usually prepared (NHJaSO, + 2KCNO 2NH4CNO + KjSO by mixing aqueous solutions of ammonium sulphate and potassium cyanate. Complete evaporation then gives a mixture of potassium sulphate and urea, from which the urea may be extracted w ith hot absolute ethanol, in which potassium sulphate is insoluble. 

Digestion. 20-25 mg. of the substance whose nitrogen content is to be estimated are weighed out in a stoppered weighing-tube and then transferred to the flask L that has been previously dried in an oven at izo C. With care, the substance may be transferred directly into the bulb of the flask without any adhering to the sides. If any material sticks on the way down, the flask should be tapped gently to cause the substance to fall to the bottom. 2 G. of the catalyst mixture (32 g. of potassium sulphate, 5 g. of mercury sulphate and ig. of selenium powder, well mixed) are added and 3 ml. of A.R. cone, sulphuric acid are measured out carefully and poured into the digestion... 

The residue in the flask is either a solution or a suspension of the potassium salt of the acid derived from the ester in diethylene glycol. Add 10 ml. of water and 10 ml. of ethyl alcohol to the residue and shake until thoroughly mixed. Then add a drop or two of phenolphthalein and dilute sulphuric acid, dropwise, until just acid. Allow the mixture to stand for about 5 minutes and then Alter the potassium sulphate. Use the clear filtrate for the preparation of a sohd derivative or two of the acid (see Section 111,85,4). 

Garside elal. (1979) measured size distributions of seeondary nuelei and reported their variation with supersaturation. Signifieant inerease of nuelei with supersaturation is observed. Thus the proeess is not simply an attrition event alone, but is also related to the level supersaturation at whieh parent erystal is growing. Jones elal. (1986) also observed anomalous growth of seeondary nuelei in a study of the eontinuous MSMPR erystallization of potassium sulphate with eonsequenees inferred for seeondary nueleation rates. Girolami and Rousseau (1986) demonstrate the importanee of initial breeding meehanism in seeded potash alum bateh erystallization. The number of erystals... 

Figure 7.3 Predicted, (a) cooling curves, and (h) transient. supersaturation for potassium sulphate solutions after Jones, 1994)...

Figure 9.3 Potassium sulphate crystals formed by. a) cooling, (h) drowning-out with acetone Jones etai, 1987)...

Figure 9.4 Population density distribution of potassium sulphate crystals from continuous cooling crystallization Jones and Mydlarz, 1989)...

Budz, J., Jones, A.G. and Mullin, J.W., 1987a. On the size-shape dependence of potassium sulphate crystals. Industrial and Engineering Chemistry Research, 26, 820-824. 

Chianese, A., Mazzarotta, B., Huber, S. and Jones, A.G., 1993. On the Effect of Secondary Nucleation on the Size Distribution of Potassium Sulphate Fine Crystals from Seeded Batch Ci-ystallization. Chemical Engineering Science, 48, 551-560. 

Jones, A.G., Budz, I. and Mullin, I.W., 1987. Batch crystallization and solid-liquid separation of potassium sulphate. Chemical Engineering Science, 42, 619-629. 

Jones, A.G. and Mydlarz, I., 1989. Crystallization and subsequent solid-liquid separation of potassium sulphate. Part I MSMPR kinetics. Chemical Engineering Research and Design, 67, 283-293. 

Jones, A.G., Chianese, A. and Mullin, J.W., 1984. Effect of fines destruction on batch cooling crystallization of potassium sulphate solutions. In Industrial Crystallization 84. Eds. S.J. Jancic and E.J. de Jong, Amsterdam Elsevier, pp. 191-194. 

Mulliii, J.W. and Garside, J., 1967. Crystallization of aluminium potassium sulphate a study in the assessment of crystallizer design data I Single crystal growth rates, II Growth in a fluidised bed. Transactions of the Institution of Chemical Engineers, 45, 285-295. 

Mydlarz, I. and Jones, A.G., 1989. On modelling the size-dependent growth rate of potassium sulphate in an MSMPR crystallizer. Chemical Engineering Communications, 90, 47-56. 

Randolph, A.D. and Cise, M.D., 1972. Nucleation kinetics of potassium sulphate-water system. American Institute of Chemical Engineers Journal, pp. 4181, 798. 

Randolph, A.D. and Sikdar, S.K., 1976. Creation and survival of secondary crystal nuclei. The potassium sulphate-water system. Industrial and Engineering Chemistry Fundamentals, 15, 64. 

Ethyl Potassium Sulphate.- T1ic romliinnimn iK-luccn... 

By the action of KCN on the alkyl iodide or ullcyl potassium sulphate,... 

Ethyl alcohol, 49 Ethyl benzene, 141 Ethyl benzoate, 209 Ethyl bromide, 54 Ethylene bromide, 62 Ethyl ether, 59 Ethyl malonate, 96 Ethyl malonic acid, 97 Ethyl potassium sulphate, 50 Ethyl tartrate, 115 rotation of, 120 Lykman depressimeter, 37... 

Salt solutions When a zinc sheet is immersed in a solution of a salt, such as potassium chloride or potassium sulphate, corrosion usually starts at a number of points on the surface of the metal, probably where there are defects or impurities present. From these it spreads downwards in streams, if the plate is vertical. Corrosion will start at a scratch or abrasion made on the surface but it is observed that it does not necessarily occur at all such places. In the case of potassium chloride (or sodium chloride) the corrosion spreads downwards and outwards to cover a parabolic area. Evans explains this in terms of the dissolution of the protective layer of zinc oxide by zinc chloride to form a basic zinc chloride which remains in solution. 

Note. Prepare the precipitating reagent by dissolving 5.0 g aluminium potassium sulphate (potash alum) in 90 mL warm water. Cool and add dropwise with stirring, while cooling in ice, a solution of 2.0 g sodium hydroxide in 5.0 mL water until the initially formed precipitate re-dissolves. After standing for 12 hours, filter, adjust the pH to 12.6, and dilute to 100 mL with water. 

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