﻿318 Profs. J. N. Mukberjee and B. 0. Papaconstantinou on 

 Variation o/Tore with Temperature. 



Similarly, by determining the times required to produce a 

 definite change in the colour o£ tbe sol for the same electrolyte 

 concentration but different temperatures, we can determine 

 the variation in e with temperature. 



From equation (3), 



we get 



2 9 - = l+£V.«.« (13) 



Since a definite change of colour is being used, ^ is 

 constant, or n 



1 + • € f t = k^, a constant. , . . (11) 



Substituting the value of j3 in (14), we get 



4 Ra . . n . ,^„ 



Since Ra, N , and n are constants, we have 



— — — = k' a constant (16) 



The viscosity of colloidal gold solutions has been found to 

 be practically equal to that of water, and the variation with 

 temperature can be assumed to be equal to that of water. 

 For different temperatures Ave have 



£j . 0! . e l _ t 2 . 6. 2 . 6 2 - 



Vi V2 



Since t x is experimentally determined and and 7) are 

 known, variations in e can be compared. 



The experimental data are given below. They are taken 

 from the same paper (pp. 1570-71). 



Table X. 



Temperatures. 



Electrolyte. Standards*. 15°. 30°. 50°. 



N/30 Potassium chloride .. V Sol. C. 5 inin. 10 -in in. 8 min. 30 sec. 



N/30 Potassium sulphate . ,, „ D. 30 sec. 10 sec. 10 sec. 



N/30 Potassium nitrate .. „ „ D. 42 ,. 18 „ 12 ,, 



* These i*efer to the protected gold sols used as standards for 

 comparison of colour. See loc. cit. 



