QUALITATIVE SEPARATIONS WITH SODIUM NITRITE IN ABSENCE OF PHOSPHATES, ETC.1

Gillett Wynkoop
1897 Journal of the American Chemical Society  
anogen held by them can be determined approxiinately from the data in series 12 and 13. Generally, with impure solutions, the results of titration by this method are more accurate than those obtained by the ordinary Liebig method ; with pure solutions the results are practically identical, and in nearly all cases the end-reaction is sharper and an estiinatioii can be more rapidly carried out I 108 grams silver, or 170 grams silver nitrate correspond to 5 2 grams cyanogen or 130 grams potassium
more » ... yanide. T h e standard silver solution used may be, with advantage, quite dilute ; preferably not over twentieth normal, or one-half per cent. silver. For technical purposes it is common to take I ~3 0 5 grams silver nitrate crystals per IOO cc. of water, when each cc. corresponds to one centigram of potassium cyanide (or four milligrams of cyanogen) ; or, taking samples of tell cc. each, one cc. of standard silver solution used represents one-tenth of one per cent. potassium cyanide in the liquid tested. If prepared by dissolving the weighed metal i t is riot generally necessary to expel all acid. Satisfactory results have also been obtained by using a standard ammoniacal silver solution. made by dissol.\.iiig pure silver i n commercial nitric acid, and adding a slight excess of ammonia.
doi:10.1021/ja02079a014 fatcat:xvgjehswbnejvgyz74wzp5spqa