Reaction with barium carbonate

Barium titanate is usually produced by the soHd-state reaction of barium carbonate and titanium dioxide. Dielectric and pie2oelectric properties of BaTiO can be affected by stoichiometry, micro stmcture, and additive ions that can enter into soHd solution. In the perovskite lattice, substitutions of Pb ", Sr ", Ca ", and Cd " can be made for part of the barium ions, maintaining the ferroelectric characteristics. Similarly, the TP" ion can partially be replaced with Sn +, Zr +, Ce +, and Th +. The possibihties for forming solution alloys in all these stmctures offer a range of compositions, which present a... 

Reactions of barium carbonate with various oxides... 

The compound Ba5[Ru2(0)n] has been synthesized by solid-state reactions of barium carbonate with ruthenium oxide. The X-ray structure shows that it contains peroxide ions and the ruthenium is in the +5 oxidation state, i.e., Ba5[Ru2(02)0g]. The novel mixed-valence Ru — Ru triple perovskites, Ba3M[Ru2(0)9] (M = Li, Na), have been grown from reactive hydroxide fluxes. ... 

Barium acetate is made by the reaction of barium carbonate with acetic acid ... 

It is relatively simple to determine the extent to which a sulfonation reaction has proceeded. The reaction mixture is neutralized with barium carbonate and treated with enough soda to form the sodium siplt. The number of sulfo groups present can be calculated from the amount of soda used up. One sulfo group requires 53 grams of NaaCOs. Calcium carbonate cannot be used for this purpose since calcium sulfate is soluble in solutions of naphthalenesulfonic acids. 

Isbell and Hudson identified lactones as the oxidation products of aldoses in buffered solution. The conditions were such that any free aldonic acid formed would be converted into the salt. Hence, lactones are the initial oxidation products and it was concluded that cyclic sugars give 5-lactones by oxidation with bromine water. The reactions were carried out in a solution buffered with barium carbonate and carbon dioxide. In the slightly acidic medium employed, the oxidation was rapid and interconversion between the anomeric forms of the sugars was relatively slow. In some cases the oxidation was 95% complete in five minutes. The extent of the reactions can be seen in Table X. 

Following the procedure described by Reutov and Shatkina (10), reaction of 1,5-dibromopentane with 90% 13C-enriched potassium cyanide provided the 1,5-dicyanide which was hydrolyzed to pimelic acid in aqueous hydrochloric acid (pure in 65% yield). This acid was then reacted with barium carbonate and the product was heated at 340° under distilling conditions for 4 hrs (10). 

EXPLOSION and FIRE CONCERNS a flammable liquid NFPA rating Health 2, Flammability 2, Reactivity 1 explosive reactions with barium peroxide, boric acid, hydrochloric acid + water, potassium permanganate incompatible with 2- amino ethanol, aniline, glycerol, hydrogen fluoride, permanganates, sodium hydroxide, sodium peroxide, sulfuric acid, water when heated to decomposition it emits toxic fumes such as acetic acid and carbon monoxide use carbon dioxide, dry chemical, water mist, or alcohol foam for firefighting purposes. 

It is reported to be a mixture of 3- and 5-sulphonate isomers. It may be prepared by the interaetion of guaiaeol with sulphuric acid at 70 to 80°C to form guaiaco sulphonic acid. After adequate dilution the reaction mixture is first neutralized with barium carbonate to remove excess of H2SO4 as a precipitate of barium sulphate and secondly, the filtrate is treated with potassium carbonate to neutralize the guaicosulphonic acid itself and also to precipitate any excess barium. The reaction mixture is filtered and the filtrate concentrated to ciystallization. 

Barium thiocyanate was first prepared by Berzelius, who roasted barium hexacyanoferrate(II) with sulfur. It has also been obtained by reaction of barium carbonate with a solution of thiocyanic acid, by conversion of ammonium thiocyanate through the copper (I) thiocyanate by consecutive reactions with copper(I) chloride and barium hydroxide, by treatment of Prussian blue with barium sulfide, and by reaction of barium sulfide, sulfur, and cyanamide. The procedure described below makes possible the preparation of barium thiocyanate in any desired quantity from barium hydroxide and ammonium thiocyanate as starting materials. The 3-hydrate, " which is obtained first, is dehydrated readily to yield anhydrous barium thiocyanate. 

BARIUM TITANATE. BaTiOj M.p. >1500°C. Pure form undergoes abrupt phase change from tetragonal to cubic at 130°C, the Curie temperature. Barium titanate is usually produced by the solid-state reaction of barium carbonate and titanium dioxide. Has widespread use in the electronics industry because of its high dielectric constant, and piezoelectric and ferroelectric properties. The high dielectric constant of BaTiOj and the ease with which its electrical properties can be modified by combination with other materials make it exceptionally suitable for miniature capacitors. 

Stability and Reactivity data from MSDSs. These data offer a wealth of information for predicting or interpreting chemical reactions that would be applicable to various courses, including general chemistry, organic chemistry, and inorganic chemistry. In particular, MSDSs from MDL Information Systems, Inc. list extensive reaction information under "Incompatibilities." For example, magnesium is incompatible with barium carbonate because of the formation of an explosive acetylide (21). Have your students write the reaction. 

Expression of the reactivities, reaction of titanium dioxide with barium carbonate... 

We illustrate the case for the formation of barium titanate through the reaction of titanium dioxide with barium carbonate according to following reaction ... 

Barium carbonate prevents formation of scum and efflorescence in brick, tile, masonry cement, terra cotta, and sewer pipe by insolubilizing the soluble sulfates contained in many of the otherwise unsuitable clays. At the same time, it aids other deflocculants by precipitating calcium and magnesium as the carbonates. This reaction is relatively slow and normally requites several days to mature even when very fine powder is used. Consequentiy, often a barium carbonate emulsion in water is prepared with carbonic acid to further increase the solubiUty and speed the reaction. 

Barium nitrite [13465-94-6] Ba(N02)2, crystallines from aqueous solution as barium nitrite monohydrate [7787-38-4], Ba(N02)2 H2O, which has yellowish hexagonal crystals, sp gr 3.173, solubihty 54.8 g Ba(NO2)2/100 g H2O at 0°C, 319 g at 100°C. The monohydrate loses its water of crystallization at 116°C. Anhydrous barium nitrite, sp gr 3.234, melts at 267°C and decomposes at 270 °C into BaO, NO, and N2. Barium nitrite may be prepared by crystallization from a solution of equivalent quantities of barium chloride and sodium nitrite, by thermal decomposition of barium nitrate in an atmosphere of NO, or by treating barium hydroxide or barium carbonate with the gaseous oxidiation products of ammonia. It has been used in diazotization reactions. 

This reaction is favored by moderate temperatures (100—150°C), low pressures, and acidic solvents. High activity catalysts such as 5—10 wt % palladium on activated carbon or barium sulfate, high activity Raney nickel, or copper chromite (nonpromoted or promoted with barium) can be used. Palladium catalysts are recommended for the reduction of aromatic aldehydes, such as that of benzaldehyde to toluene. 

Choice of catalyst and solvent allowed considerable flexibility in hydrogenation of 8. With calcium carbonate in ethanol-pyridine, the sole product was the trans isomer 9, but with barium sulfate in pure pyridine the reaction came to a virtual halt after absorption of 2 equiv of hydrogen and traws-2-[6-cyanohex-2(Z)-enyl]-3-(methoxycarbonyl)cyclopentanone (7) was obtained in 90% yield together with 10% of the dihydro compound. When palladium-on-carbon was used in ethyl acetate, a 1 1 mixture of cis and trans 9 was obtained on exhaustive hydrogenation (S6). It is noteworthy that in preparation of 7 debenzylation took precedence over double-bond saturation. 

Kasuganobiosamine (4) by Hot Alkaline Hydrolysis. An aqueous solution (150 ml.) saturated with barium hydroxide was added to a solution of kasugamycin hydrochloride (5.3 grams, 12.22 mmoles) dissolved in 50 ml. of water free from carbon dioxide. The solution was refluxed on a steam bath for 10 hours. By the similar treatment of the reaction mixture as described in the case of cold alkaline hydrolysis, ammonia (11.10 mmoles), barium oxalate (3.037 grams, 12.48 mmoles) and kasuganobiosamine (3.638 grams, 11.80 mmoles) were obtained. 

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