Electrochemical Behaviour of Dichromate Ions in Various Base Electrolytes at Dropping Mercury Electrode

Chemical Laboratories, Rajasthan University, Jaipur 302004

Manuscript received 27 February 1974; revised 5 November 1974; accepted 11 February 1975

The present investigations deal with the polarographic behaviour of dichromate ions in different base electrolytes. Solutions containing 1m M of dichromate ions in 0.1 M base electrolytes were polarographed at 30°C. The plots of id vs „\(\sqrt[]{h}\) and i_d vs C (concentration of dichro­mate ions) were linear and passing through origin for all the cases, reveals that the reductions are diffusion controlled. The plots of log i/i_d —i vs E_d._e. (—V vs S.C.E.) were linear in all systems, but the value of slope was much higher than required for 3 electron reversible reduction (20 mV). These results show the irreversibility of the electrode reaction. The electrode kinetics was studied by Koutecky's method for irreversible electrode process. The kinetic parameters for reduction of dichromate ions in all cases have been calculated. The analytical importance of the results obtained have been discussed.