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Is the positive terminal of a battery positively charged?

  1. Feb 10, 2009 #1
    Does the positive electrode of a Daniel cell (the Copper electrode) actually have a net positive charge when the electrodes are not connected by a conducting material such as a wire? If not, does it have a net charge at all and how does this charge compare to the negative terminal?

    Finally, are the answers to these questions true for every type of (galvanic) electrochemical cell??
  2. jcsd
  3. Feb 14, 2009 #2
    Any cell that I can think of functions by moving electrons from an anode to a cathode. Since it is separating a charge, the electrodes have equal and opposite charges.

    But when the circuit is open? I know that modern batteries don't retain the charges in their electrodes once the circuit is broken, but the Daniel Cell? I'm not sure... Is there a chemist in the building?
  4. Feb 15, 2009 #3
    Battery's electrodes are charged. The value of the charge is [tex] \pm Q[/tex], where [tex] Q = CV[/tex], V is battery's voltage and C is the capacitance between the electrodes. Since the capacitance C is very small, the charge Q is usually negligible.
  5. Feb 15, 2009 #4
    That's right! I never thought of the electrodes as capacitors, but I guess they are! So, does a 9V battery have more capacitance because of the way it is shaped? (the electrodes are closer together)

    I would think so.
  6. Dec 15, 2009 #5
    I've been interested in this question recently, and I was wondering if you could expand on this comment in this thread: https://www.physicsforums.com/showthread.php?t=363541"
    Last edited by a moderator: Apr 24, 2017
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