294 



Dr. G. Gore on the Molecular 



Influence of Proportion of Ingredients upon the Amount of 

 Energy. 



With the object of obtaining graphic representations of the 

 influence of proportion of ingredients, the following series of 

 measurements were made. With each mixture, 1 part by 

 weight of each ingredient was diluted with not less than 1550 

 parts of water previous to mixing. The proportions of the 

 substances employed are stated in the form of molecular 

 weights. Only the " average " amounts of voltaic energy are 

 given. 



Table XI. 



Exp. 2.— Mixture "A. 5 



HN(X 



lNa 2 S0 4 +12 

 + 12 

 + 12 

 + 12 

 + 12 

 + 12* 

 + 11 

 + 10 



Na 2 S0 4 



Exp. 3. — Mixture 



2NaNO,+6 



H 2 S0 4 at 19 



4 „ 



6 » 



8 „ 



10 „ 



12 „ 



12 „ 



12 „ 



12 „ 



12 „ 



12 „ 



12 „ 

 NaNO, 



+6 



+6 



+ 6 



+6 



+6* 



+5^ 



+5 



+4 



+3 



+2 



+ 1 



12 



3,900,941 

 136,342 

 56,724 

 43,194 

 35,934 

 33,429 

 30,872 

 35,686 

 31,250 

 27,268 

 20,813 

 13,568 

 5,453 

 163 



Each of these two series shows the depression of energy at 

 the combining proportion, attending complete chemical union 

 of the two substances. The excess of either ingredient appears 

 to exist largely as uncombined mixture. The two chief 

 causes which appear to determine the magnitudes of voltaic 

 energy are, strength of chemical union of the dissolved sub- 

 stances with zinc, and dilution of the definite compound by 

 the substance in excess ; at the combining proportion the 

 latter influence does not exist because there is no substance 

 in excess. In the upper part of each series these two causes 

 cooperate, whilst in the lower part they counteract each 

 other : in the upper part, the stronger substance being in 

 excess, enlarges the magnitudes ; in the lower part the weaker 

 one is in excess, and diminishes them. The influence of dilu- 

 tion appears to preponderate over that of chemical union 

 generally in each series. Variation of amount of excess of 

 acid has in each series a much greater effect than variation of 

 excess of salt. The following are the curves representing 

 the above numbers : — 



