Galvano-gasometric studies of magnesium in aqueous solutions

The difference effect ( Delta ) behaviour of magnesium is studied in Na sub 2 SO sub 4 , NaBr, MgSO sub 4 and MgBr sub 2 solutions up to 2.0 M concentration using galvano-gasometry set up. Comparison of the hydrogen gas evolution rates obtained from galvano-gasometry method and from the atomic absorption spectrophotometer (AAS) shows a lower value in the former. A transition from positive difference effect to negative difference effect in sodium salt solutions and its absence in magnesium salt solutions are observed during the study. The current density at which the transition occurred is termed as transition current density denoted by the symbol i sub tau . The relationship of i sub tau with the nature and concentration of the electrolytes are also discussed in this communication.