94 Conductivities and Viscosities in Pure and in Mixed Solvents. 



15, on account of its high vapor-tension. At first the titration was 

 made in beakers; later it was found that the titration could be carried 

 on very well in the bottle itself, thus eliminating a source of error. An 

 electric motor was used for stirring the baths, since the hot-air engine 

 could not be run over night. When the baths were not stirred during 

 the night, they varied as much as 0.3 or 0.4; and the position 

 of the bottles as regards the heating and cooling surfaces seemed to 

 produce a marked effect. Normal solutions of sodium and potassium 

 sulphates and of barium nitrate could not be prepared, since these 

 salts were not sufficiently soluble; therefore, they were not studied. 

 Cadmium and aluminum salts were discarded on account of their acid 

 reaction, and ammonium salts because they suppressed to nearly half- 

 value the ionization of the alkali used in the titration. The ammonium 

 salt formed by the neutralization of the acid titrated with the base 

 would also affect the ionization of the base, if the reaction was allowed 

 to proceed very far. 



CALCULATIONS. 



The results are expressed in percentages of the ester decomposed. 

 This was obtained as follows: 



In the first place the total amount of the ester per bottle was deter- 

 mined. From the mean weight of four 10 c.c. portions the weight per 

 cubic centimeter of the methyl acetate was found to be 0.9257 gram, 

 giving us 3.7028 grams as the total weight of the methyl acetate. 



Then the weight of the ester, which, on saponification, would give 

 enough acetic acid to neutralize 1 c.c. of the standard one- twentieth 

 normal ammonia, was calculated; 1 c.c. of ammonia corresponded to a 

 decomposition of 0.003543 gram of methyl acetate. Dividing this 

 value by the total amount of the ester, 3.7028 grams, we find that 1 c.c. 

 of one-twentieth normal ammonia (0.001677 gram per c.c.) represents 

 0.0957 per cent of the ester saponified. 



To get the percentage saponification for each salt, it is only necessary to 

 multiply the burette reading for each bottle by the factor 0.0957 per cent. 



For methyl formate we obtained the following values: The weight 

 per c.c. of ester, 0.9701 gram; the total weight of the ester, 1.9402 

 grams; the weight of the ester which, when saponified, corresponded 

 to 1 c.c. of the fifth-normal ammonia (per c.c. 0.007 gram) is 0.01199 

 gram, and the percentage saponification, 0.618 per cent. 



DATA. 



In the following tables of data, the methyl acetate per bottle is 4 c.c. 

 or 3.7028 grams; the methyl formate, 2 c.c. or 1.9402 grams. Table 

 56 contains the results when the baths were not stirred over night, and 

 these results have, therefore, a slight error. It was found that calcium 

 chloride and potassium nitrate, on dilution, increase, then decrease the 

 velocity of the reaction. Duplicate measurements were, therefore, 

 made with new solutions, and the results recorded in table 58. The 



