Solubility barium sulfate

Figure 6.3 Barium sulfate solubility as mg/L barium at various temperature CC) and chloride concentrations (mg/L). (Reproduced with permission from Daubert Cromwell.)...

These rosin-based sizes, whether paste, Hquid, or emulsions, can be used to size all grades of paper that are produced at acid pH. The latter include bleached or unbleached kraft Hnerboard and bag paper, bleached printing and writing grades, and cylinder board. In addition, polyaluminum compounds have been used in place of alum, most notably, polyaluminum chloride (48), which can reduce barium deposits where these have been a problem. The barium chloride by-product is more water-soluble than barium sulfate. Other polyaluminum compounds such as polyhydroxylated forms of alum and polyaluminum siHcosulfate have been evaluated as alum replacements. 

The fused product contains about 60—85% barium sulfide, unreacted barium sulfate, and impurities present in barite and ash. The soluble barium sulfide is extracted from the mixture with water and separated from the insoluble impurities by filtration. 

Extravasation of barium sulfate iato the peritoneal cavity through a perforated GI tract can produce serious adverse reactions. When a perforation is suspected, the use of a water-soluble iodinated contrast medium is iadicated. In this case, oral or rectal administration of sodium or meglumine-sodium salts of diatrizoic acid (6) and oral use ofiohexol (11) are the preferred procedures. 

In other applications of CT, orally administered barium sulfate or a water-soluble iodinated CM is used to opacify the GI tract. Xenon, atomic number 54, exhibits similar x-ray absorption properties to those of iodine. It rapidly diffuses across the blood brain barrier after inhalation to saturate different tissues of brain as a function of its lipid solubility. In preliminary investigations (99), xenon gas inhalation prior to brain CT has provided useful information for evaluations of local cerebral blood flow and cerebral tissue abnormalities. Xenon exhibits an anesthetic effect at high concentrations but otherwise is free of physiological effects because of its nonreactive nature. 

Quantitatively, sulfur in a free or combined state is generally determined by oxidizing it to a soluble sulfate, by fusion with an alkaH carbonate if necessary, and precipitating it as insoluble barium sulfate. Oxidation can be effected with such agents as concentrated or fuming nitric acid, bromine, sodium peroxide, potassium nitrate, or potassium chlorate. Free sulfur is normally determined by solution in carbon disulfide, the latter being distilled from the extract. This method is not useful if the sample contains polymeric sulfur. 

In metallic form, barium is very reactive, reacting readily with water to release hydrogen. In aqueous solution it is present as an ion with a +2 charge. Barium acetate, chloride, hydroxide, and nitrate are water-soluble, whereas barium arsenate, chromate, duoride, oxalate, and sulfate are not. Most water-insoluble barium salts dissolve in dilute acids barium sulfate, however, requkes strong sulfuric acid. 

Barium sulfate [7727-43-7] BaSO, occurs as colorless rhombic crystals, mp 1580 °C (dec) sp gr 4.50 solubihty 0.000285 g/100 g H2O at 30°C and 0.00118 at 100°C. It is soluble in concentrated sulfuric acid, forming an acid sulfate dilution with water reprecipitates barium sulfate. Precipitated BaSO is known as blanc fixe, prepared from the reaction of aqueous solutions of barium sulfide and sodium sulfate. 

Water-insoluble barium salts are poorly absorbed. In fact, barium sulfate is used as a contrast material for x-ray examination of the gastrointestinal tract based on its limited solubility andlow toxicity (52). Barium sulfate fed to mice at various levels up to 8 ppm dietary Ba ( 1.14 mg/kg-d as Ba " ) for three generations had no significant effects on growth, mortality, morbidity, or reproductive performance (53). 

Treatment. Treatment of poisoning from soluble barium salts may be preventive or curative (47,51). Preventive treatment involves inhibition of intestinal absorption by administering such soluble sulfates as magnesium or sodium, causing precipitation of barium sulfate in the alimentary tract. 

Chemical scaling is another form of fouling that occurs in NF and RO plants. The thermodynamic solubility of salts such as calcium carbonate and calcium and barium sulfate imposes an upper boundary on the system recovery. Thus, it is essential to operate systems at recoveries lower than this critical value to avoid chemical scaling, unless the water chemistry is adjusted to prevent precipitation. It is possible to increase system recovery by either adjusting the pH or adding an antisealant, or both. 

One way to establish equilibrium between a slightly soluble solid and its ions in solution is to stir the solid with water to form a saturated solution. As you might expect, the solubility of the solid, s, in moles per liter, is related to the solubility product constant, Ksp. In the case of barium sulfate dissolving in water we have... 

How would you expect the solubility of barium sulfate in water BaS04(s) Ba2+( q) + S042 (aq)... 

According to the flowchart, salts of chloride and sulfate are soluble. Therefore, no precipitate will form unless one of these compounds is included among the exceptions listed in Table 4A - Barium sulfate is one of these exceptions, so it is an insoluble salt. 

The solubility guidelines can be used to design ways of making salts. Suppose that we want to prepare barium sulfate, BaSOq. This substance is opaque to X rays, so it is often used to visualize the intestinal tract. Patients are given a barium cocktail, and then the areas of interest are irradiated. Barium sulfate absorbs the X rays to give a picture of the intestines. Soluble barium salts are poisonous, but BaSOq is insoluble in water, so it can be administered safely. (Only 1.0 X 10" mol dissolves in 1 L ofwaterat25 °C.)... 

A source of soluble cations is required for the s mthesis of barium sulfate. We can use any barium salt that... 

C18-0073. For the following salts, write a balanced equation showing the solubility equilibrium and write the solubility product expression for each (a) silver chloride (b) barium sulfate (c) iron(H) hydroxide and (d) calcium phosphate. 

Thennodynamic inhibitors are complexing and chelating agents, suitable for specific scales. For example, for scale inhibition of barium sulfate, common chemicals are ethylenediaminetetraacetic acid (EDTA) andnitrilotriacetic acid. The solubility of calcium carbonate can be influenced by varying the pH or the partial pressure of carbon dioxide (CO2). The solubility increases with decreasing pH and increasing partial pressure of CO2, and it decreases with temperature. 

This equation may be interpreted to mean that any soluble barium salt will react with any soluble sulfate to produce (insoluble) barium sulfate. 

The limited solubility (5, moles per liter) of barium sulfate is reflected in the solubility product for the dissolution. The solubility can be calculated to show that a small amount of barium ion is found free in solution ... 

Thus, by an application of the common ion effect, the solubility of barium sulfate has been reduced to produce 104-fold less free barium ion in solution, thus further reducing the risk of barium toxicity. 

A water-soluble sample of a solid containing some barium nitrate is to be analyzed for barium. The barium is to be precipitated as barium sulfate. Answer the following questions about this experiment. 

Certain miscellaneous observations have a bearing on our discussion of differences in taste reactions. For example, it is well recognized in hospitals that, although a barium sulfate emulsion is perfectly tasteless and innocuous to many individuals, to others it is very disagreeable. It would appear that the taste threshold for barium sulfate varies from individual to individual and that this substance is soluble enough to give a sensation of taste to some individuals. 

Barium sulfate, BaS04, is a sparingly soluble ionic compound that is used to enhance X-ray imaging. 

Consider barium sulfate, a sparingly soluble salt. X-ray technicians give patients a barium sulfate suspension to drink before taking an X-ray of the large intestine. A suspension of barium sulfate is opaque to X-rays, which helps to define this part of the body. (See Figure 9.4.)... 

Compounds Soluble—barium nitrate, barium sulfide, barium chloride, barium hydroxide, barium acetate insoluble—barium sulfate... 

The 2003 ACGIH threshold limit value-time-weighted average (TLV-TWA) for barium, and soluble barium compounds, as Ba is 0.5mg/m for barium sulfate it is lOmg/m for total dust containing no asbestos and <1% silica. 

All barium salts, especially the water and acid-soluble compounds, are highly toxic. Barium ion can cause death through ventricular fibrillation of the heart. It is a stimulant to the heart muscle. Intake of a few grams of barium salt can be lethal to humans. The insoluble salts such as barium sulfate, however, have little toxic action. 

Impurities such as heavy metal sulfides are filtered out. Water-soluble sulfur compounds are oxidized to insoluble barium sulfate and removed. The solution is then evaporated to crystaUize barium chloride. 

Barium hydroxide decomposes to barium oxide when heated to 800°C. Reaction with carbon dioxide gives barium carbonate. Its aqueous solution, being highly alkahne, undergoes neutrahzation reactions with acids. Thus, it forms barium sulfate and barium phosphate with sulfuric and phosphoric acids, respectively. Reaction with hydrogen sulfide produces barium sulfide. Precipitation of many insoluble, or less soluble barium salts, may result from double decomposition reaction when Ba(OH)2 aqueous solution is mixed with many solutions of other metal salts. 

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