A mixture of copper and gold metals that is subjected to electrorefining contains tellurium as an impurity. The standard reduction potential between tellurium and its lowest common oxidation state, Te4+, is Te4+1aq2 + 4 e- ¡ Te1s2 E°red = 0.57 V Given this information, describe the probable fate of tellurium impurities during electrorefining. Do the impurities fall to the bottom of the refining bath, unchanged, as copper is oxidized, or do they go into solution as ions? If they go into solution, do they plate out on the cathode?

Video transcript

Hello everyone. So in this video we're dealing with a radium. Standard reduction potentials given by this equation here as well as palladium. Standard reduction potential given this equation right over here, we're also concerning the iridium impurities during electro refining. So let's go ahead and recall that if we have a more positive standard reduction potential, then we have a substance that's easily reduced. And if that's the case then we have a stronger oxidizing agent. Now if our standard reduction potential is going lower or more negative value, then of course it will have the opposite effect, meaning the substance is easily oxidized, making it a stronger reducing agent. Now let's go ahead and compare the standard reduction potentials of iridium and palladium of course in its ionic form. So of course we're given these two values. If we compare those two values, we see that Iridium has a higher or a more positive potential value, which means it's more prone to a reduction than palladium does. Let's go ahead and keep note of this as well. So iridium has a higher more positive value. Then palladium. So radium will be hard to oxidize and palladium. So then a radium will not be oxidized during electoral refining and it will accumulate with the other impurities. Therefore then to answer our question here, when palladium is oxidized, Iridium impurities remain at the bottom of the refining bath. Therefore right here, this is going to be my final answer for this problem. Thank you all so much for watching