306 



PHYSICAL PROPERTIES 



The temperature-coefficient of the process is seen to be very 

 high, the velocity-constant being multipHed about 15 times by 

 10 degrees rise in temperature (from 60-70.4 degrees). The 

 relationship between the temperature and the value of K is very 

 satisfactorily represented by the Arrhenius equation : 





K, 



a relation which, although not strictly deducible from the gas 

 laws (60) is analogous in form to the van't Hoff equation con- 

 necting the value of the equilibrium-constant with the tempera- 

 ture and which is deducible from the gas laws. We are probably 

 justified in concluding, therefore, as we did in the analogous 

 case afforded by the variation in the dissociation-constant of 



