Silver compounds acid, base properties

The oxides of metals and non-metals can be characterized by their acid-base properties. Oxygen forms compounds with all the elements except the noble gases. It reacts directly with all elements except the halogens, a few noble metals, such as silver and gold, and the noble gases. 

The product HCl is measured by acid-base titration. An aliquot of the product mixture is analyzed for chloride ion by ion chromatography or titration with a standard solution of silver nitrate. The compound can be identified from its physical properties. 

Elemental composition P 38.73%, H 1.26%, O 60.01%. The compound may be identified by physical properties alone. It may be distinguished from ortho and pyrophosphates by its reaction with a neutral silver nitrate solution. Metaphosphate forms a white crystalline precipitate with AgNOs, while P04 produces a yellow precipitate and P20 yields a white gelatinous precipitate. Alternatively, metaphosphate solution acidified with acetic acid forms a white precipitate when treated with a solution of albumen. The other two phosphate ions do not respond to this test. A cold dilute aqueous solution may be analyzed for HPO3 by ion chromatography using a styrene divinylbenzene-based low-capacity anion-exchange resin. 

In contrast to the other elements of group 13, thallium is considered a soft acid in Pearson s soft/hard acid classification (see Hard Soft Acids and Bases).This makes the element and its derivatives unique, and leads to its potentially most outstanding feature the properties of thallium are a subtle blend of some of the most desirable properties of numerous other metals (e.g. heavy alkali metals, silver, mercury, and lead). Thallium compounds are stable in both oxidation states (-1-1 and -1-3). The trivalent cation is quite a strong oxidation reagent, since it is reduced to T1+ easily (standard redox potential E°(TP+ — Tl" ") = -1.25 V). The ease of this reduction is utilized in certain organic reactions. 

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