Abstract: As one of the important concepts in the electrochemical part in physical chemistry, the determination of ion migration number is involved in the physical chemistry experiment course in various universities. Literature research and our past teaching practices have shown that the ion migration number measured using the Hittorf method differs significantly from the literature values. In order to reduce the measurement errors and investigate the influencing factors of the test results, this experiment made improvements in three aspects: controlling the amount of solution, the sequence of solution/electricity disconnection, and the calculation of the quantity of electricity. After minimizing the errors caused by experimental operations and concentration measurement, the factors that truly influence the measurement results of ion migration number were analyzed. The experimental results indicated that when using current multiplied by time as the data source for the quantity of electricity and calculating the ion migration number using the cathodic solution, the obtained results were closer to the reference value.

Key words: Ion migration number, Hittorf method, Influencing factors, Spectrophotometry