Is the positive terminal of a battery positively charged?

Click For Summary

Discussion Overview

The discussion centers around the charge characteristics of the positive terminal of a Daniel cell, specifically whether it has a net positive charge when not connected by a conductor. Participants also explore whether these characteristics apply to all types of galvanic electrochemical cells.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question whether the positive electrode of a Daniel cell has a net positive charge when the electrodes are not connected, and if it has any net charge at all.
  • There is a suggestion that in an open circuit, modern batteries do not retain charges in their electrodes, but uncertainty remains regarding the behavior of the Daniel cell.
  • One participant proposes that all electrochemical cells function by moving electrons from an anode to a cathode, implying that the electrodes have equal and opposite charges when connected.
  • Another participant introduces the concept that the electrodes can be viewed as capacitors, discussing the relationship between charge, voltage, and capacitance, while questioning if the shape of a 9V battery affects its capacitance.

Areas of Agreement / Disagreement

Participants express uncertainty about the charge characteristics of the electrodes in an open circuit, with no consensus on whether the positive terminal retains a net positive charge or how this applies across different types of galvanic cells.

Contextual Notes

There are limitations regarding the assumptions about charge retention in open circuits and the definitions of charge and capacitance in the context of electrochemical cells.

Who May Find This Useful

This discussion may be of interest to those studying electrochemistry, battery technology, or anyone curious about the behavior of charges in electrochemical cells.

p.tryon
Messages
51
Reaction score
0
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??
 
Physics news on Phys.org
p.tryon said:
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??

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?
 
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.
 
meopemuk said:
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.

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.
 
Archosaur said:
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?

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:

Similar threads

  • · Replies 58 ·
2
Replies
58
Views
6K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 36 ·
2
Replies
36
Views
7K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 14 ·
Replies
14
Views
6K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 21 ·
Replies
21
Views
2K