QUANTITATIVE ANALYSIS. 



QUANTITATIVE ANALYSIS OF SOME INORGANIC 

 COMPOUNDS. 



i. DETERMINATION OF THE SULPHURIC ACID IN 

 COPPER SULPHATE, CuS0 4 +5H 2 0. 



Grind some perfectly pure copper sulphate in a mortar, 

 dry it by pressing between filter-paper, weigh off exactly 

 about 0.5 g. and place in a beaker (weigh a cork- or glass- 

 stoppered weighing-tube approximately to centigrams 

 introduce about 0.5 g., then weigh accurately, shake out the 

 contents of the tube into a beaker and weigh again). Dis- 

 solve in 100 cc. of water, acidify with a few drops of hydro- 

 chloric acid, and heat on the wire gauze till it begins to boil. 

 Heat to boiling about 10 cc. of barium chloride solution, 

 .acidified with a drop of hydrochloric acid, and cautiously 

 add it to the copper sulphate solution. Heat the mixture 

 on the water-bath until the barium sulphate has completely 

 settled, filter through an ash-free, thin filter of 9 cm. diameter 

 (Schleicher and Schiill's, No. 590, or DreverhoiFs "ash-free 

 baryta-filter-paper," No. 400 or No. 412), and collect the 

 precipitate without any loss on the filter with the aid of warm 

 water and a glass rod, the end of which is covered with a piece 



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