Solid samples bringing into solution

When working with a solid sample, it often is necessary to bring the analyte into solution by dissolving the sample in a suitable solvent. Any solid impurities that remain are removed by filtration before continuing with the analysis. 

An impure sample of potassium ferrate, K2Fe04, may be prepared as follows Dissolve sufficient ferric chloride, FeCl3,6H20, to correspond to 40 g. Fe(OH)3 in 2 1. of hot water and precipitate the hydroxide with potassium hydroxide. Wash the precipitate repeatedly with hot water by decantation until nearly all chlorides have been removed and evaporate the suspended hydroxide to a volume of about 65 cc., bringing it into a porcelain dish that will hold about 250 cc. Break up 25 g. of solid potassium hydroxide into small pieces and add it to the ferric hydroxide, warming the mixture to insure solution. 

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