Section 94. Summary of Equivalent Conductances. 



?59 



Table 107. Equivalent conductance of hydrochloric acid. 



The degree of concordance of the results of the experiments carried 

 only to 156 may be first considered. An examination of the preceding- 

 tables shows that for sulphuric, phosphoric, and nitric acids and potas- 

 sium hydrogen sulphate in solutions 2 milli-normal and stronger, the 

 agreement between the initial and final values at 18, and between dupli- 

 cate experiments is in general better than 0.3' per cent, the greatest differ- 

 ence being 0.22 per cent. The same is also true of the 0.2 milli-molal phos- 

 phoric acid and of the 0.5 milli-normal nitric acids. In the 0.2 and 0.5 

 milli-normal sulphuric acid solutions, however, the final values at 18 are 

 somewhat larger than the initial, averaging 0.5 and 0.3 per cent respec- 

 tively. The independent experiments at these two concentrations agreed 

 within about the same limits, the greatest average deviation from the mean 

 being 0.22 per cent. Kato's values (table 101) show about the same differ- 

 ences as our own between the intial and final 18 values, except in three 

 experiments which show an increase of about 1 per cent. A comparison 

 of his individual experiments with one another can hardly be made owing 

 to large differences in concentration, but his final means compared after 

 reducing to round concentrations agree with our own within 0.2 per cent, 

 except at 100 in the 0.5 and 2.0 milli-normal where the differences reach 

 0.4 per cent. The divergence between the initial and final 18 values for 

 barium hydroxide increases rapidly with the dilution, amounting to 0.4 

 per cent at 100 milli-normal, 1.2 per cent at 50 milli-normal, 8 per cent at 

 2 milli-normal, and 38 per cent at 0.5 milli-normal, in cases where the solu- 

 tion had been heated to 156. These large changes in the dilute solutions 

 make, of course, the observed values of the conductance at the higher 

 temperatures very inaccurate ; but the error has been doubtless reduced to 

 a relatively small amount (except for the 0.5 milli-normal solution) by 

 the correction applied for the contamination as described in section 91. 



