698 



find for the algebraic sum of the entropies free from concentration 

 mailing use of the expressions of § 2 : 



2nH,^l z= 2(//,=:i)monat. — (^^r=l)diat. = 



113 3 nijiniB ^^ , 



_ _ RInT-\ — RlnR RlnN-{-- Mn — Rlnh — 



2 2 2 2 mA-\-mB 



3 1 

 Rln2 mnjt~-RlnM-\- C\, 



2 2 



in which C\ amounts to V, R when Sackur's values are used, to 

 7j R when Tetrode's values are used. 



Sackur and Tetrode's calculations are based on the following 

 assumptions for the specific heats : 



3 _5 



Co monat. ^^^ ^ ^ 'i ^v dial. ~ R' 



The value of the transformation energy in its dependence on the 

 temperature is therefore given b}^ : 



^nE = ^?iEt=o + V. RT. 



In this expression and the following the molecular values ?i of 

 the substances of the second member of the chemical reaction equa- 

 tion are always taken positive, tliose of the first member negative. 



Inserting these values into the expression for /C, we find: 

 RT Iv K, = - 2:7iEt=o — V. RT + TSnH„=^i - RT, 

 in which ^^nH,=i is represented by the above derived expressions. 

 We can transform this expression as follows : 



lnK, = -^^^-^^lnT-lnM-]-lnC,, ... (4) 

 Rl ^ 



in which 



3 . ?n 4 m/i , ^ , ,, . 1 , , ^ 



InC, = - In ^JlllL'::^ In 2Nh + - Ink - - In 2;r + C« ; (4a) 



2 w?,4 -f" rriB ^ ^ 



C, amounting to — 1 according to Sackur's expressions, to according 

 Tetrode. 



4. In the fifth communication on the law of partition of energy 

 Prof. VAN der Waals Jr. derives the following equation for the 

 dissociation equilibrium of a di-atomic molecule: 



f — f 



7?t; \mA \ tns J M h 2v 2jr 



ej — f„ here represents the transformation energy at the absolute 

 zero for one particle; n^ and n^ represent the number of split and 

 unsplit molecules per volunie unity; hence we get: 



