19what is the electrolyte,here ?
Assume that impure copper contains only iron,silver and gold as impurities.after passsage of 140 amp, for 482.5 sec, the mass of the anode decreased by
22.260 grams and the cathode increased its mass by 22.011 grams.Estimate the % iron and the % copper originally present.(Some amount of hydrogen eveolved at cathode).
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2 Answers
11Only reactive metals such as Fe and Cu , oxodosed at anode.
Fe → Fe 2+ + 2e-
Cu → Cu 2+ + 2e-
Ag and Au , being non reactive will appear below anode as anode mud.
Inc in mass at cathode is due to Cu depositied. = 22.011 g = 0.3466 mol
Moles of Fe and Cu dissolving frm anode = itn X 96500 (where i = current and t = time)
= 140 X 482.52 X 96500 = 0.3500 mol
Moles of Fe dissolved = 0.3500 - 0.3466 = 0.0034 mol = 0.1904 g
Now % of Fe = 0.190422.260 X 100 = 0.86 5
and that of Cu = 22.011 X 10022.260 = 98.88 %
