Hexammino-chromic nitrate

Hexammino-chromic Iodide, [Cr(NII3)G]I3, is also formed by the decomposition of the nitrate. A solution of hexammino-chromic nitrate is shaken with solid potassium iodide, the precipitate formed is washed with hydriodic acid, dissolved in cold water, and repreeipitated with dilute acid. It separates in yellow rhombic plates and is sparingly soluble in cold water. On warming with hydriodic acid iodo-pent-ammino-iodide is not produced.1... 

EXERCISE 71. HEXAMMINO-CHROMIC NITRATE, [Cr(NH3)3] (N03)3 CHLORO-PENTAMMINO-CHROMIC CHLORIDE, [Cr(NH3)3Cl]Cl2... 

To the united filtrate add concentrated nitric acid, precipitating the hexammino salt (formerly called luteo-chromic nitrate). Filter off this salt, dissolve it in a little warm water to which a few drops of nitric acid has been added, and again precipitate the crystalline hexammino-chromic nitrate by the addition of nitric acid and by cooling. The yield is about 7 g. 

Hexammino-chromic Bromide, [Cr(NH i)(i]Or3, is precipitated from a concentrated solution of the nitrate of the series by decomposing it with concentrated hydrobromic acid. The orange-yellow plates which separate are decanted from the solution, washed with dilute hydrobromic acid and then with water. It is easily soluble in pure water but sparingly so in presence of hydrobromic acid. The transformation of the salt into bromo-pentammino-chromic bromide on heating with acid takes place more slowly than the analogous reaction with the chloride of the series. 

Hexammino-ehromic Chloride, [Cr(NH3)6]Cl3.H20, is produced by the addition of concentrated hydrochloric acid to a solution of the nitrate, or, better, by the decomposition of the mercury double salt, [Cr(NH3)6]Cl3.(HgCl2), with hydrogen sulphide, when a purer chloride is obtained.3 It is formed as one of the products of the action of liquid ammonia on anhydrous violet chromic chloride.4... 

To convert the hexammino nitrate into the pentammino chloride, mix a solution of the hexammino nitrate dissolved in eleven times its weight of hot water with an equal volume of concentrated hydrochloric acid and boil gently for 30 min. to 1 hr. Cool the solution, filter off the precipitated chloro-pentammino-chromic chloride, and wash and dry as above. 

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