Ok, so as my title is really vague, here is the detailed question. So, basically the cathodic reaction for a dry cell is NH4++MnO2+H2)+e-->Mn(OH)3+NH3, according to my textbook anyway (I've found different reactions online which is annoying, so if I'm wrong just say). Now, here the Manganese is the element being reduced, and Carbon isn't present anywhere in these equations. So why, if my textbook is right, would the graphite rod be the cathode? I would have assumed the bit with the Manganese dioxide in it is the actual cathode, and the graphite rod just allows for electrons to reach it as graphite is conductive?
Cathode of a dry cell? (1 Viewer)
- Thread starter calamebe
- Start date
The cathode or anode in these redox reactions do not have to be involved in the reaction. Like for example in a galvanic cell when we have a platinum electrode it is inert and only provides a surface upon which for the reaction to occur, but is not involved in the actual reaction.
For the reaction equation at the cathode your textbook might say that but I would use this 2MnO2(s) + 2NH4+ + 2e- --> Mn2O3 (s) + H2O(l) + 2NH3. Because it has featured in HSC exam answers made by bostes before
For the reaction equation at the cathode your textbook might say that but I would use this 2MnO2(s) + 2NH4+ + 2e- --> Mn2O3 (s) + H2O(l) + 2NH3. Because it has featured in HSC exam answers made by bostes before