Calcium aqueous solubility

The Krafft point, i.e., the aqueous solubility, also depends greatly on the type of counterion [30,60,61]. For example, potassium salts have higher Krafft points than sodium or ammonium salts. Bivalent cations, like calcium and magnesium, raise the Krafft point. The rise is smaller for ester sulfonates than for alkyl sulfates [61]. 

Over the eons, the flow and evaporation of water inside a cavern creates a stunning array of rock sculptures. Stalagmites grow upward from the floor, sometimes joining stalactites to form massive columns. Limestone dams create beautiful pools of water. Limestone draperies fall like curtains from water flowing around overhanging rock. Delicate mineral flowers sprout from the walls. All these features result from the aqueous solubility equilibrium of calcium carbonate. 

In cement paste, the residual concentration of calcium resinate is approximately 0.5 gl i in the aqueous phase, which compares well with the aqueous solubility of calcium caprate, as shown in Fig. 3.11. It will be noted that the C9 fatty acid has a solubility of about 1 gl whilst the is about 0.05 gl h The solubility of calcium... 

Tommaseo, C. E. Kersten, M. 2002. Aqueous solubility diagrams for cementitious waste stabilization systems. 4. Mechanism of zinc immobilization by calcium silicate hydrate. Environmental Science and Technology, 36, 2919-2925. 

Saccharin is acidic and not very soluble in water. For improved solubility, the food industry prefers the sodium or calcium [6485-34-3] salt. Sodium saccharin [128-44-9] is so widely used that it is often referred to simply as saccharin. The aqueous solubilities of both salts are about the same, ie, 0.67 g/mL. Saccharin, stable to heat over a wide pH range, can withstand most food processing (qv) conditions. Interactions between saccharin and other food ingredients have not been reported. 

The hydrolysis process, ie, reaction with water, for lime is called slaking and produces hydrated lime, Ca(OH)2. Calcium hydroxide is a strong base but has limited aqueous solubility, 0.219 g Ca(OH)2/100 gH20, and is therefore often used as a suspension. As an alkali it finds widespread industrial application because it is cheaper than sodium hydroxide. 

Commercial applications of calcium chloride and its hydrates exploit one or more of its properties with regard to aqueous solubility, hygroscopic nature, the heat gained or lost when one hydrated phase changes to another, and the depressed freezing point of the eutectic solution at a composition of about 30% by weight calcium chloride. 

It is an everyday experience that calcium soaps have a low aqueous solubility while many surfactants with monovalent counterions have an extremely high solubility. As for other compounds, the solubility is to a great extent given by conditions in the solid phase, but for surfactants the strongly cooperative association produces the peculiar temperature dependence of solubility schematized in Fig. 2.8. The so-... 

In cement paste, the residual concentration of calcium resinate is approximately 0.5 gl1 in the aqueous phase, which compares well with the aqueous solubility of calcium caprate, as shown in Fig. 3.11. It will be noted that the C fatty acid has a solubility of about 1 gl1, whilst the C is about 0.05 gl1. The solubility of calcium dodecyl sulfate is approximately 0.1 gl1, so it is indicated that the optimum value lies in the region of 0.1- 0.5 gl 1 solubility of the calcium salt. It is interesting to note that the abilities of the soluble sodium and insoluble calcium salts to entrain air in cement pastes are very similar [6] (Figs 3.12 and 3.13). 

Figure 5 A graphical correlation of calcium bromide solubility in the organic phase versus its activity in the aqueous phase at different temperatures (0.5 M TOA +. 0.5 M 2-ethylhexanoic acid.

Fig. 3.7 Composition of liquid phase in the system CaO-SiOj-HjO according to different authors. (After [11]) Jennings H.M., Aqueous Solubility Relationships for Two Types of Calcium Silicate Hydrate , J. Am Ceram. Soe. 69, 614 (1986), published by John Wiley Sons Ltd, reproduced with the permission of Wiley Sons...

The solubility of calcium phosphate depends on the type of amino acid product used, the type of calcium and phosphate salts used, temperature, magnesium concentration, and the final volume of the admixture. The pH of the parenteral nutrition admixture influences the equilibrium between the trivalent phosphate ion and its monobasic (H2P04 ) and dibasic (HP04 ) forms. The aqueous solubility of the monobasic and dibasic calcium phosphate amounts to 18 g/L and 0.3 g/L, respectively. At the physiological pH of 7.4 about 60 % of the phosphate exists in the poorly soluble dibasic form. If the pH of the nutrition admixture is lower than pH 6.4, the monobasic form is the predominant one and the chance of precipitation is diminished (see Sect. 18.1.1). 

Not all salts exhibit a good aqueous solubility. A number of inorganic salts having a relatively low molecular weight and a low water solubility are listed in Table 18.6. Also the solubility product often is given (Table 18.7). This allows us to determine the effect of other ions in the solution on the solubility of a given substance, for example, when sodium carbonate is added to a solution of magnesium chloride. Also the reduction of the solubility of the poorly soluble calcium carbonate can be calculated when a certain amount of the readily soluble sodium carbonate or calcium chloride is added. This reduction in the solubility of, in this case, calcium carbonate is also known as the common ion effect. 

Li, Z., and Demopoulos, G. P. (2002). Calcium Sulfate Solubility in Concentrated Aqueous Chloride Solutions. Chloride Metal. 2, 561 -574. 

Deliquescence and efflorescence. A substance is said to deliquesce (Latin to become liquid) when it forms a solution or liquid phase upon standing in the air. The essential condition is that the vapour pressure of the saturated solution of the highest hydrate at the ordinary temperature should be less than the partial pressure of the aqueous vapour in the atmosphere. Water will be absorbed by the substance, which gradually liquefies to a saturated solution water vapour will continue to be absorbed by the latter until an unsaturated solution, having the same vapour pressure as the partial pressure of water vapour in the air, is formed. In order that the vapour pressure of the saturated solution may be sufficiently low, the substance must be extremely soluble in water, and it is only such substances (e.g., calcium chloride, zinc chloride and potassium hydroxide) that deliquesce. 

In the isolation of organic compounds from aqueous solutions, use is frequently made of the fact that the solubility of many organic substances in water is considerably decreased by the presence of dissolved inorganic salts (sodium chloride, calcium chloride, ammonium sulphate, etc.). This is the so-called salting-out effect. A further advantage is that the solubility of partially miscible organic solvents, such as ether, is considerably less in the salt solution, thus reducing the loss of solvent in extractions. 

Lithium Hydroxide. Lithium hydroxide monohydrate [1310-66-3], Li0H-H2 0, is prepared industrially from the reaction of lithium carbonate and calcium hydroxide in aqueous slurries. The calcium carbonate is subsequently separated to yield a lithium hydroxide solution from which lithium hydroxide monohydrate can be crystallized. Lithium hydroxide is the least soluble alkaH hydroxide, and solubiHty varies Htfle with temperature. 

A Phenylamino)phenol. This phenol (17) is slightly soluble ia ethanol, diethyl ether, acetone, benzene, and water. The compound is made by heating resorciaol and aniline at 200°C ia the preseace of aqueous phosphoric acid or calcium chloride. Ia another process, 3-amiaophenol is heated with aniline hydrochloride at 210—215°C (181). 

---