Bismuth salts

Solutions of many antimony and bismuth salts hydrolyse when diluted the cationic species then present will usually form a precipitate with any anion present. Addition of the appropriate acid suppresses the hydrolysis, reverses the reaction and the precipitate dissolves. This reaction indicates the presence of a bismuth or an antimony salt. 

When hydrogen sulphide is bubbled into an acidic solution of an antimony or a bismuth salt an orange precipitate, SbjSs, or a brown precipitate, BijS, is obtained. Bismuth(III) sulphide, unlike antimony(IIl) sulphide, is insoluble in lithium hydroxide. 

One-part urethane sealants (Table 3) are more compHcated to formulate on account of an undesirable side reaction between the prepolymer s isocyanate end and water vapor which generates carbon dioxide. If this occurs, the sealant may develop voids or bubbles. One way to avoid this reaction is to block the isocyanate end with phenol and use a diketamine to initiate cure. Once exposed to moisture, the diketamine forms a diamine and a ketone. The diamine reacts with the isocyanate end on the prepolymer, creating a cross-link (10). Other blocking agents, such as ethyl malonate, are also used (11). Catalysts commonly used in urethane formulations are tin carboxylates and bismuth salts. Mercury salt catalysts were popular in early formulations, but have been replaced by tin and bismuth compounds. 

Bismuth trioxide may be prepared by the following methods (/) the oxidation of bismuth metal by oxygen at temperatures between 750 and 800°C (2) the thermal decomposition of compounds such as the basic carbonate, the carbonate, or the nitrate (700—800°C) (J) precipitation of hydrated bismuth trioxide upon addition of an alkah metal hydroxide to a solution of a bismuth salt and removal of the water by ignition. The gelatinous precipitate initially formed becomes crystalline on standing it has been represented by the formula Bi(OH)2 and called bismuth hydroxide [10361 -43-0]. However, no definite compound has been isolated. 

Bismuth Salts. Bismuth trioxide dissolves in concentrated solutions of strong oxyacids to yield bismuth salts. In more dilute solutions of strong acids or in solutions of weak acids, the oxide reacts to form bismuthyl or basic salts. The normal salts are very susceptible to hydrolysis. 

Bismuth. 25.0 mL bismuth ion solution + solid hexamine to pH about 4.6 the precipitate of basic bismuth salt dissolves as the EDTA solution is added but the titration is slow. 

The amount of precipitated bismuth decreased as the concentration of bismuth salt increased (Table 9.16) and the duration of sonication required to bring about hydrolysis also increased. The initial reaction was spontaneous as per Eq. (9.111), which, however, seemed to be facilitated by ultrasonic cavitation at high concentration of bismuth. Since the H+ ions were also produced during the formation of bismuthyl ion, at the point where the sum of concentration of H+ ions present initially and formed by Eq. (9.110) was equal to the concentration required to shift the equilibrium of Eq. (9.111) towards left side, the hydrolysis did not occur even after sonication. 

Bismuth salts are thought to be effective in peptic ulcer disease because they have bactericidal properties against... 

The answer is d. (Hardman, pp 909-910.) It is now recognized that infection with fi pylon is a major etiologic factor in peptic ulcer disease. Bismuth salts are bactericidal for many organisms but especially for spirochetes. Colloidal bismuth salts such as bismuth subsalicylate also have a coating or cytoprotective action. Antimicrobials and GI antisecretory drugs are also used in combination with bismuth compounds. 

Mercaptoethanol reacts rapidly with most bismuth salts with the typical mineral acid metathesis to give bis(thiolate) Bi(SCH2 CH2OH)2X derivatives as the prominent and most easily isolated... 

Bismuth salts, 4 25 Bismuth sesquisulfide, 4 24 Bismuth subcarbonate, 4 36 Bismuth subgallate, 4 36 Bismuth subhalides, 4 19 Bismuth subnitrate, 4 36 Bismuth subsalicylate, 4 1, 36 medical applications of, 22 11-12 Bismuth(III) sulfate, 4 25 Bismuth(III) sulfide, 4 24 Bismuth sulfides, 4 24-25 Bismuth thiolates, 4 25 Bismuth-tin alloy waterfowl shot, 4 15 Bismuth triacetate, 4 25 Bismuth tribromide, 4 21 physical properties of, 4 20t Bismuth trichloride, 4 19-20 physical properties of, 4 20t Bismuth trifluoride, 4 19 physical properties of, 4 20t Bismuth trihalides, 4 19 Bismuth triiodide, 4 21-22 physical properties of, 4 20t Bismuth trinitrate pentahydrate, 4 25 Bismuth trioxide, 4 23-24 physical properties of, 4 20t Bismuth triperchlorate pentahydrate, 4 25... 

Basic nitrate is usually found as an impurity in bismuth salts (e.g., bismuth subcarbonate), very often due to the mode of preparation from the metal via bismuth nitrate. 

Drugs that may affect tetracyclines include antacids containing aluminum, calcium, or magnesium iron salts zinc salts barbiturates bismuth salts carbamazepine cholestyramine colestipol phenytoin rifamycins urinary alkalinizers (eg, sodium lactate, potassium citrate). 

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