222 Dr. Meyer Wilderman : Connexion between the 



or 



Is 



ill* 



4-(^H/ + W JV-^H 3 01g^+(^K 3 // -n 1 K^-7 ?2 K/0].(n) 



/. <?., the fact that each o£ the components has two potentials 

 instead of one does not therefore affect the form of the 

 equation obtained for chemical equilibrium. 



Here ( —=- . — : I —7- J gives the connexion between 



/m/Vi /wg'Ya /mA«j • 



the concentrations of the gaseous substances expressed in 

 gram-molecules per unit volume acting chemically one upon 

 another under the action of light, which constitutes the law 

 of mass-action in homogeneous systems ; 



(« 1 H 1 '+« 1 H I '-ii,H,0 \gf+ (» 3 K 3 "-n 1 K 1 "-» 2 K 2 / ') 



the difference between the thermal energy of n x gram-mol. of 

 °"i + ^2 gram-mol. of a 2 and the thermal energy of the 

 product of their combination (n 3 gr.-mol. of <7 3 ) in light of a 

 given intensity and composition, i. e., 2-9 the heat of reaction, 

 (let it be denoted by Q,.) in light, when n-i gr.-mol. of 

 a x -\-n 2 gr.-mol. a 2 transform into n z gr.-mol. of cr 3 ; 

 w 8 K 3 "— WjK,"— 7? 2 K 2 // =K iv is a constant ; —fa + ^—n^Ut' 

 is the work done by the system or against the same during 

 the same transformation in light, and t' is the absolute 

 temperature. 



Thus an ordinary consideration of Gibbs' equations under 

 the modified conditions (i. e., wJien each component gets under 

 the action of light a light-kinetic potential besides its modified 

 chemical potential) sJiows that the connexion between the 



logarithm of I -j- ) . (-7-) : ( — j- ) 9 or the logarithm of the 



constant of chemical equilibrium in homogeneous systems in 

 light, the heat of reaction or of transformation of n^x + n 2 a 2 

 into w 3 <7 3 in light, the external work done by the system or 

 against the same daring the reaction, and the absolute tern- 

 perature remains the same and follows in light the same law 

 as in the dark, — i. e., a system which is in equilibrium in the 

 dark, u'hen exposed to light passes under the influence of the 

 some only to a new point of equilibrium, has a new constant of 



