AbstractThe fundamental aspects of the extraction and stripping of platinum (II) from its chloride solution by Aliquat 336 diluted with toluene have been studied. The extraction and stripping was at 99.5 and 97.6% equilibrium within 30 s and 20 min respectively. The percentage extraction increased slightly with decreasing hydrochloric acid concentration. In 0.1 mol dm−3hydrochloric acid, 1.0 volume percent Aliquat 336 in toluene could load 9.8 mmol dm−3of platinum (II). The percentage stripping of platinum (II) from Pt(II)‐load organic solvent increased with increasing sodium bisulphite concentration. The enthalpy changes of extraction and of stripping were 12.8 and 114.9 kJ mol−1respectively. Both of the reactions were endo