Precipitation of barium sulfate

Sulfamic acid and its salts retard the precipitation of barium sulfate and prevent precipitation of silver and mercury salts by alkah. It has been suggested that salts of the type AgNHSO K [15293-60 ] form with elemental metals or salts of mercury, gold, and silver (19). Upon heating such solutions, the metal deposits slowly ia mirror form on the wall of a glass container. Studies of chemical and electrochemical behavior of various metals ia sulfamic acid solutions are described ia Reference 20. 

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. 

Precipitation of barium sulfate from a mixture of barium chloride and sulfuric acid. 

The photo in the margin shows a cloudy precipitate of barium sulfate forming as solutions of barium chloride and magnesium sulfate mix. 

Fisher, R.B. and Rhinehammer, T.B. (1953) Rapid precipitation of barium sulfate. Anal Chem., 25, 1544-1548. 

Wagner, W.F. and Wuellner, J.A. (1952) Homogeneous precipitation of barium sulfate by hydrolysis of sulfamic acid. Anal. Chem., 24, 1031-1032. 

To 33.2g of pure (recrystallized) sulfamic acid (No. 92) in 250ml of water are added 54.0g of pure barium hydroxide 8-hydrate. When all the solids have dissolved, any precipitate of barium sulfate is filtered off and the clear filtrate evaporated in vacuo at room temperature with the water pump. Successive crops of crystals are isolated, washed with 95% alcohol and the mother liquor with rinsings is further evaporated. Depending on the completeness of the water removal, yields of over 90% are readily attained. 

Figure 8.16 When barium chloride solution is added to sodium sulfate a white precipitate of barium sulfate forms.

You have seen that barium sulfate is an insoluble salt (p. 125). Therefore, if you take a solution of a suspected sulfate and add it to a solution of a soluble barium salt (such as barium chloride) then a white precipitate of barium sulfate will be produced. 

The salts of sulfuric acid, sulfates, can be identified by a simple test-tube reaction. To test for a sulfate, add a few drops of dilute hydrochloric acid to your unknown followed by a few drops of barium chloride. If a sulfate is present, a white precipitate of barium sulfate forms. 

Sulfate A salt of sulfuric acid formed by the reaction of the acid with carbonates, bases and some metals. It is possible to test for the presence of a sulfate by the addition of dilute hydrochloric add and some barium chloride solution. A white precipitate of barium sulfate is formed if a sulfate is present. 

An alternative procedure for the study of neptunium oxidation states at trace concentrations has been described by Inoue and Tochiyama (1977). They showed that, in the pH range 6-7, Nplv may be quantitatively absorbed on silica gel whilst Npv remains in solution. In acid solution, however, a precipitate of barium sulfate selectively absorbs Nplv leaving the higher oxidation states in solution. The authors gave no environmental data for neptunium in their publication but Nelson and Orlandini (1979) subsequendy adapted the procedure to demonstrate that the dominant oxidised plutonium species in natural waters is Puv and not Puvl. 

Water Silver nitrate Barium chloride Peroxydisulfates, S2082- On boiling, decomposes into the sulfate, free sulfuric acid, and oxygen Black precipitate of silver peroxide On boiling or standing for some time, forms precipitate of barium sulfate... 

Barium chloride Sulfates, S042- White precipitate of barium sulfate insoluble in warm dilute hydrochloric acid and in dilute nitric acid slightly soluble in boiling hydrochloric acid... 

White precipitate of barium carbonate soluble in dilute acids White precipitate of barium oxalate soluble in dilute acids Heavy, white, finely divided precipitate of barium sulfate White precipitate of barium sulfate... 

L of the acidified acetone-water solution was sufficient to elute the A-4696 activity from the carbon column. The eluate containing the A-4696 activity as treated with a saturated barium hydroxide solution, in order to form a precipitate of barium sulfate, thus removing the sulfate ions from the solution. The mixture was filtered and the barium sulfate precipitate was discarded. The filtrate containing the A-4696 activity was concentrated under vacuum to dryness. The resulting residue comprising the A-4696 activity amounted to approximately 80.0 g. 

The paint industry is the largest single consumer of barium compounds. Barium sulfide and zinc sulfate solutions are mixed to give a precipitate of barium sulfate and zinc sulfide, which is heat treated to yield the pigment lithopone. Barium chlorate and nitrate are used in pyrotechnics to impart a green flame. Barium chloride is applied where a soluble barium compound is needed. 

The sulfate anion, S042, reacts with barium chloride, BaCl2, to form a white precipitate of barium sulfate, BaS04. 

You will need to use the following double displacement reaction. This reaction produces a precipitate of barium sulfate. 

Such methods are wet oxidation of pulp followed by estimation of sulfate by precipitation of barium sulfate (Canadian Pulp and Paper Association Standard G28 1970), X-ray fluorescence spectroscopy (Rivington 1988, Kibblewhite et al. 1987), and combustion of pulp followed by analysis of sulfur as sulfur dioxide or as sulfate. The sulfur dioxide evolved is determined by iodometric titration (Canadian Pulp and Paper Association useful method G.7U, March 1959). Sulfate can be determined by titration with barium chloride (Ora 1960), back-titration with sulfuric acid after addition of barium perchlorate (Aldrich 1974), potentiometric titration with lead perchlorate using an ion-selective electrode (Ross and Frant 1969), or ion chromatography (Douek and Ing 1989). 

The only definitely known halous acid, chlorous acid, is obtained in aqueous solution by treating a suspension of barium chlorite with sulfuric acid and filtering off the precipitate of barium sulfate. It is a relatively weak acid (KA <= 10 2) and cannot be isolated in the free state. Chlorites (MC102) themselves are obtained by reaction of C102 with solutions of bases ... 

Sulfur is determined gravimetrically by precipitation of barium sulfate after oxidation of an approximately 50-mg. sample by fusion with a sodium peroxide-sodium carbonate mixture in a nickel crucible. 

On the assumption that heterogeneous nucleation is the important process, precipitation of barium sulfate from a supersaturated solution can be viewed as beginning by a series of steps on a nucleation site ... 

Nucleation Fischer found that, in PFHS, nucleation takes place early and only growth occurs thereafter. In the homogeneous precipitation of barium sulfate by sulfate generation from sulfamic acid in a solution containing 0.01 Af barium ion, he found (Section 8-2) that the number of particles was sensibly constant from the beginning to the end of precipitation. Evidently nucleation was complete within the first small fraction of the total precipitation time. From the rate of sulfate generation it... 

Samples of dry solid potassium sulfate, K2SO4, and dry solid barium nitrate, Ba(N03)2, can be mixed with no appreciable reaction occurring for several years. But if aqueous solutions of the two are mixed, a reaction occurs rapidly, forming a white precipitate of barium sulfate. 

Fig. 3 Impact of different feed positions on the precipitation of barium sulfate. The selectivity to by-product as a percent of reactant is shown for feed into zones of high and low turbulent energy dissipation. The impeller speed and reactant addition time were held constant. More by-product is formed at feed points where the local mixing is slow.

The white crystalline precipitate of barium sulfate is filtered, washed with water, ignited, and weighed. 

The method is silent about the final volume of reaction solution, which should be specified because it also determines the effective acidity before the precipitation of barium sulfate. Some of the acid is consumed in dissolution and evap-... 

Goswami and Chandra identify sources of error in the determination of sulfur trioxide in gypsum by the precipitation of barium sulfate, and recommend a... 

Make the volume of the reaction solution up to 400 to 500 mL before precipitation of barium sulfate. 

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