1/20/2024 0 Comments White precipitate![]() ![]() The silver iodide is so insoluble that ammonia cannot lower the silver ion concentration enough for the precipitate to dissolve. The more concentrated ammonia pushes the equilibrium even further to the right, lowering the silver ion concentration even more. This occurs with silver chloride, and with silver bromide if the ammonia is concentrated. If the adjusted silver ion concentration multiplied by the halide ion concentration is less than the solubility product, some precipitate dissolves to restore equilibrium. The effect of adding the ammonia is to lower this concentration still further. The equation for this reaction is given below:Ī solution in contact with one of the silver halide precipitates contains a very small concentration of dissolved silver ions. This is a reversible reaction, but the complex is very stable, and the position of equilibrium lies well to the right. The ammonia combines with silver ions to produce a complex ion called the diamminesilver(I) ion, +. The compounds are all quite insoluble, but become even less so down the group. The table below lists solubility products from silver chloride to silver iodide (a solubility product for silver fluoride cannot be reported because it is too soluble). Enough solid is always precipitated to lower the ionic product to the solubility product. : either of two mercury-ammonia compounds: a. If the product of the concentrations exceeds this value, a precipitate is formed.Įssentially, the product of the ionic concentrations is never greater than the solubility product value.If the product of the concentrations of ions is less than the solubility product, no precipitate is formed.The square brackets indicate molar concentrations, with units of mol L -1. For the silver halides, the solubility product is given by the expression: Expected results: White solid particles will form and deposit as a precipitate. ![]() This value is known as the solubility product. Slowly add the sodium carbonate solution to the Epsom salt solution. A precipitate forms if the concentrations of the ions in solution in water exceed a certain value, unique to every compound. There are no absolutely insoluble ionic compounds. Precipitate is insoluble in ammonia solution of any concentration Precipitate is almost unchanged using dilute ammonia solution, but dissolves in concentrated ammonia solution to give a colorless solution Precipitate dissolves to give a colorless solution ![]() The white crystalline precipitate formed on the corneal surface after topical administration of 0.3% ciprofloxacin ophthalmic solution exhibited bacterial inhibitory activity, indicating that the precipitate may function as a drug depot.\)Ĭonfirming the precipitate using ammonia solutionĪmmonia solution is added to the precipitates. It was almost the same in the solutions from cases 5 and 6. The antibacterial activity (microg/ml) determined by microbiologic assay was not related to the actual amount of ciprofloxacin in the solutions as estimated by HPLC in cases 1, 2, 4, and 7. Ciprofloxacin was not detected by either method in the precipitate obtained from one patient. Microbiologic assay was performed by agar diffusion method against Klebsiella pneumoniae.īy HPLC, concentrations of ciprofloxacin were estimated to be 1.5-60 microg/ml in the dissolved precipitate obtained from six patients, whereas the concentrations based on microbiologic assay varied from 1.6 to 16.1 microg/ml. Quantification by high-performance liquid chromatography (HPLC) and microbiologic assay of ciprofloxacin in the precipitate solutions were done. White crystalline precipitate formed on the corneal surface of seven patients was scraped and individually dissolved in sterile distilled water. To determine the antibacterial activity of the white crystalline precipitate formed on the corneal surface after topical administration of 0.3% ciprofloxacin ophthalmic solution by microbiologic assay.
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