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Hello my fellow M kitties,
For the longest time, I've been confused about anodes and cathodes, and no amount of Googling has resolved it.
Ok, so I understand that in electrolytic and galvanic cells, reduction occurs at the cathode and oxidation occurs at the anode. This means electrons are stripped from the anode and moved to the cathode. My confusion is about whether the anode has a positive or negative charge.
From what I understand, if electrons are moving away from something, then it must have a positive charge unless there was some force extracting the electron. Wikipedia takes this concept and makes it really vague, and I'm just confused:
# In a galvanic cell (drawing) the cathode is the positive electrode, where conventional current flows outwards. This outwards current is carried internally by positive ions leaving the electrolyte. It is continued externally by electrons moving inwards, negative charge moving one way amounting to positive current flowing the other way.
# In an electrolytic cell, the cathode is the negative terminal, which sends current back to the external generator.
==> Questions:
1) What is the difference between an electrode and a terminal?
2) Does this mean the cathode is positively charged in a galvanic cell and negatively charged in an electrolytic cell?
3) This may make more sense if you've taken CBT10: when a question simply talks about a cathode and an anode without regards to electrochemical cells, what is the charge on the anode?
I think that's about it, thanks, and happy studying 31st'ers!
For the longest time, I've been confused about anodes and cathodes, and no amount of Googling has resolved it.
Ok, so I understand that in electrolytic and galvanic cells, reduction occurs at the cathode and oxidation occurs at the anode. This means electrons are stripped from the anode and moved to the cathode. My confusion is about whether the anode has a positive or negative charge.
From what I understand, if electrons are moving away from something, then it must have a positive charge unless there was some force extracting the electron. Wikipedia takes this concept and makes it really vague, and I'm just confused:
# In a galvanic cell (drawing) the cathode is the positive electrode, where conventional current flows outwards. This outwards current is carried internally by positive ions leaving the electrolyte. It is continued externally by electrons moving inwards, negative charge moving one way amounting to positive current flowing the other way.
# In an electrolytic cell, the cathode is the negative terminal, which sends current back to the external generator.
==> Questions:
1) What is the difference between an electrode and a terminal?
2) Does this mean the cathode is positively charged in a galvanic cell and negatively charged in an electrolytic cell?
3) This may make more sense if you've taken CBT10: when a question simply talks about a cathode and an anode without regards to electrochemical cells, what is the charge on the anode?
I think that's about it, thanks, and happy studying 31st'ers!
