6 Physical Chemistry 6.6 Electro Chemistry
P3060401
Transference numbers
Transport and electrode processes during electrolysis of diluted nitric acid.
Principle
Power supply, universal
Cations and anions contribute to charge transport in electrolytic processes in accordance with their different mobilities in an electric field. Hittorf transport numbers characterise the fraction of the total charge transported by a particular ion during electrolysis. They enable the calculation of ionic conductivities, the values of which are important in electrochemical practice. Transport numbers are to be experimentally determined from the characteristic concentration changes which take place at the cathode and the anode during electrolysis. Task Determine the Hittorf transport numbers for hydronium and nitrate ions from measurements resulting from the electrolysis of an 0.1 molar nitric acid solution. What you can learn about ▪ ▪ ▪ ▪ ▪
Electrolysis Faraday's laws of electrolysis Charge transport Ion mobility Hittorf numbers
Function and Applications Versatile heavy duty power supply which can also be used as a constant current supply in schools, laboratories or workshops. Equipment and technical data
Main articles Power supply, universal Multi-range meter w.overl.prot. Digital thermometer, NiCr-Ni, -50...+1300°C Double U-tube w.frits+cock, GL25 Glass beaker, short, 5000 ml Retort stand, h = 750 mm Set of Precision Balance Sartorius CPA 623S and measure software, 230 V
13500-93 07021-01 07050-00 44451-00 36272-00 37694-00
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▪ Direct current source: Stabilised, regulated output direct voltage, continuously adjustable from 0...18 V ▪ Adjustable current limit between 0...5 A ▪ LED display for constant current operationn ▪ Permantely short-circuit proof &protected against exterior voltages ▪ Alternative voltage output: Multitap transformer 2...15V, outputs galvanically separated from mains grid
49224-88
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13500-93
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