The effect of platinum(IV) on the coulometric generation of tin(II)

The current efficiency of tin(II) generation has been measured for various electrolytes and electrodes. The best results (>99.9%) were obtained with the paraffin-impregnated graphite electrode in 2M CaCl(2) + 0.2M HCl + 0.2M SnCl(4). In titrations of platinum(IV) with electrogenerated tin(II) in an electrolyte containing chloride or bromide it was found that the presence of platinum(II) or (IV) interferes in the cathodic generation of tin(II). The platinum is reduced to the elemental state at the electrode and causes simultaneous generation of hydrogen which decreases the current efficiency. This effect is more pronounced in chloride media.