formic acid in nitric acid
to a solution of 2.5 g Bi in 250 ml very diluted aq. HNO3; 40 ml of 90 percent formic acid and 50 g urea are added, filled up with water to 550 ml and brought to boil;; washing the precipitate with warm water after cooling; large excess of formic acid causes contamination of the product by metallic Bi;;
参考文献
Cartwright, P. F. S.
Analyst (Cambridge, United Kingdom), 1960 , vol. 85, p. 216 - 220
in water
an aq. solution of Bi nitrate is exactly neutralized with (NH4)2CO3; boiled for 5 minutes to remove CO2 completely; 20 ml of a 40 percent aq. solution of NH4HCO2 is added and the mixt. brought to boil;; slow cooling (on a water bath) and washing of the precipitate with hot water;;
参考文献
Kallmann, S.
Ind. engng. Chem. Anal. Edit., 1941 , vol. 13, p. 897 - 900
Chaplygina, N. M.; Itkina, L. S.
Russian Journal of Inorganic Chemistry (Translation of Zhurnal Neorganicheskoi Khimii), 1981 , vol. 26, p. 1667 - 1668
Zhurnal Neorganicheskoi Khimii, 1981 , vol. 26, p. 3118 - 3120
