A short manual of analytical chemistry, qualitative and quantitative,--inorganic and organic . ing transferred to a flask, and 100 of water inall being used to entirely transferthe powder from the mortar to theflask. In dealing with very hardsubstances, like beans, peas, etc.,the water should be used flask and contents are nowheated on the water bath for halfan hour, with frequent shaking,to entirely gelatinise the whole is then cooled, and50 of standard baryta waterhaving been added from theburette, the flask is corked, wellshaken for two minutes, proo
A short manual of analytical chemistry, qualitative and quantitative,--inorganic and organic . ing transferred to a flask, and 100 of water inall being used to entirely transferthe powder from the mortar to theflask. In dealing with very hardsubstances, like beans, peas, etc.,the water should be used flask and contents are nowheated on the water bath for halfan hour, with frequent shaking,to entirely gelatinise the whole is then cooled, and50 of standard baryta waterhaving been added from theburette, the flask is corked, wellshaken for two minutes, proofspirit is added up to the 250 , and the whole again shaken,tightly corked, and set aside tosettle. While settling a check ismade on 10 of the barytawater mixed with 50 of freshlyboiled distilled water, by titratingwith the decinormal HCl, in thepresence of two drops of phenol-phthalein. The number of of acid usedis recorded, giving the total strength of 10 of the baryta water the main analysis has settled, 50 of the clear liquid are drawn off. Fig. 45- FOOD ANALYSIS. 173 with a pipette, rapidly titrated with the decinormal acid and phenol-phthalein,and the number of of acid used is deducted from the check, and thedifference in of acid is first multiplied by 5 and then by 0324, whichgives the amount of starch in the 2 grammes taken for analysis. 10. Free Sulphuric Acid in Vinegar. To a dilute solution of methyl violet add a drop of vinegar. A blue colorshows the presence of a mineral acid in the sample. Mix 50 of the vinegar with 25 of volumetric solution of sodiumhydrate, made decinormal by diluting the normal volumetric solution to tentimes its bulk with water. The whole is evaporated to dryness, andincinerated at the lowest possible temperature. 25 of vigintinormalsolution of oxalic acid (made to exactly balance the sodium hydrate solution)are now added to the ash, the liquid heated to expel CO2, and fil
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Keywords: ., bo, bookcentury1800, bookdecade1890, booksubjectchemistryanalytic
