The Hittorf method for determining transport numbers

In this method an electrolysis experiment is set up. The passage of direct current causes changes in concentration around each electrode as a result of  

The Hittorf apparatus is hlled with a solution of known concentration. A known current is then passed through the solution for a known time from which the quantity of electricity 

Solution around each electrode can easily be run off for analysis 

The technique can be illustrated by considering what happens when a solution of AgNOa is electrolysed in a Hittorf apparatus with silver electrodes. The quantity of electricity passed is /f/96485 faraday where the current is in amp and the time in seconds. 

Chemical reaction Ag(s) — Ag+(aq) + e Migration N03 (aq) migrates to the anode solution 

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Fig. 2.6. The Hittorf method for determining transport numbers. In the diagram the passage of a current I for time t is shown. It is assumed that t+ +1 = 1. The electrolytic cell is divided into three compartments.

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