Conductivities of Some Unusual Salts. 



153 



SODIUM DIHYDROGEN PHOSPHATE. 



The solution of this salt was standardized by the method discussed 

 in connection with the trisodium phosphate. (See table 83.) 



SODIUM TUNGSTATE. 



The original solution of sodium tungstate was standardized by pre- 

 cipitating the tungstic acid as mercurous tungstate. On ignition, this 

 yields the trioxide of tungsten, which can be weighed. (See table 84.) 



SODIUM FORMATE. 



In a cold acid solution, permanganate acts only slowly with formic 

 acid, while in a hot solution the latter is lost by volatilization. In spite 

 of statements to the contrary, oxidation by means of permanganate in 

 an alkaline solution is a most unsatisfactory process. This led to the 

 use of an indirect method of standardization for the sodium formate 

 solution. An excess of standard permanganate solution was measured 

 from a burette into an alkaline solution of the formate. After standing 



TABLE 84. Sodium tungstate. 



TABLE 85. Sodium formate. 



