1892.] Formation and Decomposition of Nitrous Acid. 51 



The table below contains the results of another set of experiments 

 'with a more dilute solution. 



Series XXXIII. 



Temperature, 21'8. Nitrous acid = 0'7292 gram. Nitric acid = 

 1-5457 grams. Ratio = 1 : 2-02. 



Series XXXIV. 



Temperature, 31'8. Nitrous acid = 2'4557. Nitric acid = 2-2571. 

 Ratio of nitrous to nitric acid = 1 : 0"93. 



The greatest difference between the observed and calculated results 

 is shown in the first two experiments, but this can in part be accounted 

 for by the difficulty experienced in introducing the nitrous acid solu- 

 tion into the permanganate before that some of the liquid was pro- 

 jected from the measuring vessel by the rapidly evolved nitric oxide 

 gas. The above three series of experiments show that whether the 

 nitrous acid, produced from nitrogen peroxide and water, is of a 

 concentration of 0'45 per cent., or five times that amount, the rate of 



E 2 



