Deliquescent salts

The presence of moisture on steel above the critical humidity but below the saturation point may be caused by an adsorption mechanism or by the presence of particles of deliquescent salts on the surface. Once rusting has begun, the composition of the rust already formed will influence the relative humidity at which further rusting will occur, because rusts formed in polluted atmospheres contain hygroscopic salts. The method by which moisture reaches the surface is probably less important, however, than the length... 

Arfwedson prepared lithium acetate, ignited it, and noted the insolubility of the resulting lithium carbonate in water and its action on platinum. He also prepared and studied the bicarbonate, sulfate, nitrate, chloride, tartrate, borate, hydroxide, and a double sulfate which he reported as lithium alum. He mentioned that lithium hydroxide is much less soluble than the other caustic alkalies and that it has a greater saturation capacity [lower equivalent weight] than they. Because of its ability to form deliquescent salts with nitric and hydrochloric acids, Arfwedson recognized the close relation between the new alkali and the alkaline earths, especially magnesia. 

Wagner, J., E. Andrews, and S. M. Larson, Sorption of Vapor Phase Octanoic Acid onto Deliquescent Salt Particles, J. Geophys. Res., 101, 19533-19540 (1996). 

N. A. E. Millon4 prepared soln. of potassium chlorite and 8odium chlorite by adding chlorous acid slowly and gradually to a soln. of the alkali hydroxide until the product has a yellow colour. By rapidly evaporating the soln. to complete dryness, a deliquescent salt was obtained which, at 160°, decomposes into chlorate and chloride. This decomposition occurs if the soln. be slowly evaporated in vacuo. If an excess of chlorous acid is used with the potash-lye, a red liquid is obtained which gives off the acid on evaporation, and leaves a residue of the neutral salt. It has been suggested that the red liquid is a soln. of acid potassium chlorite. 

The iodide of ammonium thus prepared ilq a very deliquescent salt, very soluble in water and,alcohol. By keeping, even in diffused deylight when out of contact, with air, it decomposes, turning brownish-yellow,... 

A brown, deliquescent salt, yielding a turbid solution with water, due to the almost invariable presence of some basic salt. Regarding the quantitative determination, see the note under Palladium. 

Precisely weighed samples of 2 (ca. 2 mmol), or 4 (ca. 1 mmol), or 7 (1.00 mmol) were placed in a ball mill under argon together with the precise equivalent of la-c, or lb, or 6, respectively. The Teflon gasket was closed with a torque of 50 Nm and ball-milling started for 1 h. The deliquescent salts 3, 5, 8 were quantitatively obtained and collected and stored under dry argon. 

Effect of Deliquescent Salt Additives on the Reaction of S02 with Ca(OH)2... 

Table III shows the experimental results of Ca(0H)2 with deliquescent salts as additives, at 74 and 54% relative humidity. From the results presented in this table we can see that the beneficial effect of salts depends on the type of salt and the relative humidity.

At high relative humidity (74%) all the deliquescent salts tried were successful in increasing the reactivity of the Ca(0H)2 towards SO2. At lower relative humidity (54%) some of the salts do not perform as well, and some, such as Ca(1 03)2, do not have any beneficial effect at all. 

Table III Effect of Deliquescent Salts in Ca(0H)2 Reactivity and Deliquescent Properties of the Salts...

This was demonstrated in one of the early experiments where deliquescent salts of Cd and Ni were used for the preparation of the mixed analyte standards. When standard addition instead of the conventional standardization techniques was used, their concentrations were changed from 986 to 803 ug/ml and from 1520 to 1260 ug/ml for Cd and Ni, respectively. These changes in the nominal concentration can account for the observed differences therefore, preparation and standardization of mixed analyte standard solutions is very important for the evaluation of the flame-related phenomena Comparing the characteristics of the calibration curves obtained under various flame conditions with single and mixed analyte standards is a direct, effective way of determining the magnitude of the effect of the flame-related phenomena on the analytical method. 

Potassium diammonium phosphate, K(NH4)2P04,4H20, is obtained by passing ammonia into a cooled solution of potassium dihydrogen phosphate, and filtering rapidly in an atmosphere of ammonia. On exposure to air, the deliquescent salt evolves ammonia, but it can be preserved in sealed tubes.3 Other double salts with sodium,4 and with lithium6 and potassium,6 have been prepared. 

Silver perchlorate, AgC104.—The monoxide dissolves in perchloric acid, forming the perchlorate. It is also produced by double decomposition from barium perchlorate and silver sulphate. The unstable, deliquescent salt melts at 486° C., and decomposes at higher temperatures. 

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