The electrochemical equivalent of pure silver - a value of the Faraday

Oxygen-free high-pu rity samples were used in a precise deter mina tion of the electrochemi cal equival ent of silver . A comprehensive mass spec trometric analysis for impurities was performed . Our value agrees well wi th prior meas urements of the same qua ntity at th e Na ti onal Bureau of Sta ndards (NBS) by Craig and coworke rs_ We find the elec troc hemi cal equivalent of pure silver to be 1.1179648 mg C-')8S' Attached to this figur e is an unce rtainty whose random co mponent (standa rd deviation of th e mean of 8 deter minati ons) is 9.5 X 10-7 mg Co, (0.85 ppm). Th e roo t-sum-squ are of systema tic uncertainties of known origin is 1.07 X 10-6 mg Co, (0.96 ppm). The above value for the elec trochemical equival ent of silver'leads us to cal culate th e Faraday to be: F = 96486.33 (24) AN B s . s . mol-' (2.5 ppm).