Abstract: A newer, faster, inexpensive and convenient quantitative method for the determination of p-phenylene diamine using photochemical exchange reaction of sodium nitroprusside has been investigated. Sodium nitroprusside is a photolabile complex and it undergoes photochemical ligand exchange reactions rapidly. Some recent efforts have been made to utilise such reactions for the estimation of some nitrogen containing anions and electron rich organic molecules. The progress of the reaction is observed spectrophotometrically. The effects of different parameters like pH, change of concentration of sodium nitroprusside, concentration of ligands, light intensity etc. on percentage error was investigated. The efforts were made to minimise the percentage error and some optimum conditions were obtained. Such reaction can be used for the determination of p-phenylene diamine in the range of mill moles to micromoles, hence it is important to know whether such estimations can be done successfully and that to with the desired accuracy.
 

Keywords: Photochemical exchange reaction, p-phenylene diamine, sodium nitroprusside, quantitative, percentage error, optimum conditions.