morey: benzoic acid as standard 307 



ducted so to be as free from error as possible. Weight burettes 

 were used for all titrations, which were made in a 300-cc. flask 

 thru which passed a stream of air free from carbon dioxide. A 

 one-per cent solution of phenolphthalein was used as indicator 

 in all the titrations. 



Direct standardizations of hydrochloric acid. The hydrochloric 

 acid was first standardized in its preparation, having been pre- 

 pared by the method of Hulett and Bonner, 3 which is based on 

 the constancy of composition, at a definite atmospheric pressure, 

 of the constant boiling mixture formed by hydrochloric acid 

 and water. From the data given by Hulett and Bonner, the 

 resulting solution was calculated to contain 0.0036396 gram HC1 

 per gram solution, corresponding to a 0.1N factor of 0.9980. 



The next standardization was by the silver chloride method 

 with a 50-gram sample. The lxydrochloric acid in the filtrate 

 and washings was determined with the nephelometer and the 

 amount found added to that calculated from the weight of silver 

 chloride. Four concordant determinations by this method gave 

 the value 0.0036611 gram HC1 per gram solution, corresponding 

 to a 0.1 N factor of 0.9984. 



The hydrochloric acid was standardized from the sulfuric acid 

 by comparing the two solutions thru a solution of sodium hydrox- 

 ide. The mean of six determinations of the ratio HC1: NaOH 

 was 1.0464; of four determinations of the ratio H 2 S0 4 , 0.8454; 

 the ratio H 2 C1: H 2 S0 4 was therefore 1.2378. For the gravimetric 

 standardization of the sulfuric acid a 50-gram sample was taken. 

 After igniting and weighing in the usual manner the precipitates 

 were tested for occluded barium chloride b}/ - the method of Hulett 

 and Duschak, 4 but the amount found was always less than 0.1 

 milligram, a negligible quantity. The 0.1N factor for the HC1 

 calculated from these determinations was 0.9984. 



The standardization by means of sodium oxalate was made 

 after a series of experiments made to compare various samples 

 of sodium oxalate. While concordant results were obtained by 

 strict adherence to a certain procedure in the transformation 



3 Hulett and Bonner: Jour. Am. Chem. Soc, 31: 390-393. 1909. 



4 Zeits. anorg. Chem., 40: 196. 1904. 



