Traces of aniline, C6H5NH2, in drinking water can be determined by reaction with an excess of electrolytically generated Br2:

The polarity of the working electrode is then reversed, and the excess Br2 is determined by a coulometric titration involving the generation of Cu(I):
Br2 + 2Cu+ ( 2Br¯ + 2Cu2+
Suitable quantities of KBr and CuSO4 were added to a 25.0-mL sample containing aniline. Calculate the number of micrograms of C6H5NH2 in the sample from the data:

Transcribed Image Text:

NH2 NH2 Br Br +3H+ + 3Br 3Br2t Br aniline Working Electrode Functioning As Anode Cathode Generation Time with Constant Current of 1.51 mA, min 3.76 0.270