﻿LEAD FROM PER CHLORATE BATHS 



31 



remains approximately constant. It does not corrode glass or eartli- 

 emvare vessels, Avhich is an advantage, at least in laboratory work. 

 It conducts the electric current extremely well. Perchloric acid 

 solution has a conductivity near that of hydrochloric acid and 

 greater than sulphuric acid. 



HCl ' 

 HCIO, 

 H,SO, 

 HoSiF. 



Oram 

 Equivalents 

 per Liter. 



0.03 



0.0312 



0.03 



Per Cent 

 Composition. 



0.109 

 0.313 

 0.147 



Eqr.ivalent 

 Condii<-tivity 



at 18° in 

 C. O. S. units, 

 XIO' 



3581 

 . 3840 

 2673 



Five per cent greater 

 than HoSOi.' 



, I.— Photograph showing the general appearance of leau cathodes 



FROM LEAD PERCHLORATE BATHS. 



The specific conductivity of perchloric acid of about 35 per cent 

 strength^ is 0.8895 (temp. 40°) compared-^ with 0.8257 (25°) for 

 sulphuric acid of maximimi conductivity (30 per cent). 



^Whetham, Theory of Solutions, pp. 410, 436, 437 (1902). 

 ^Betts, LeacI Refining 'by Electrolysis, p. 21. 

 '•' Unpublished work by A. F. O. Germann, in this hxboratory. 

 Tower, Conductivity of Liquids, p. 35. 



