Electrichemical cell question!

[osumc2014]

Do electrons always flow from anode to cathode? no matter what the charge of anode and cathode is?

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[Raryn]

Do electrons always flow from anode to cathode? no matter what the charge of anode and cathode is?

The cathode is positive.

The anode is negative.

How could the charges be different?

 

[jh8cw]

OP,

I think you are asking the question in the context of galvanic and electrolytic cells? If you are, then yes - in both cases electrons flow from anode to the cathode (where reduction occurs).

I'm not quite certain at what is being hinted in response but: In galvanic cells: + (cathode), - (anode). In electrolytic cells: + (anode), - (cathode), this is due to difference between physics and chemistry conventions (probably thanks to Ben Franklin).

I also faintly remember the conventions for electrophoresis follows the convention such that negatively charged proteins move toward the anode.

Hope this helps.

 

[futuredoctor10]

Electrons flow from anode to the cathode always as indicated above!

I also faintly remember the conventions for electrophoresis follows the convention such that negatively charged proteins move toward the anode.

Yes, I think negatively charged proteins and DNA moves to the anode in electrophoresis. I remember a EK or Kaplan question which I missed thinking "minus to the cathode" from electrolytic/galvanic cells.

 

[FutureScaresMe]

Electrons flow from anode to the cathode always as indicated above!


Yes, I think negatively charged proteins and DNA moves to the anode in electrophoresis. I remember a EK or Kaplan question which I missed thinking "minus to the cathode" from electrolytic/galvanic cells.

As long as you think of an anode as havin a negative core and positive shell, it explains why electrons move from anode to cathode (electron repulsion) and why anions, DNA, etc. move towards the anode (positive attraction)

 

[rnicholsaz]

In a galvanic cell (spontaneous) the electrons flow to the cathode (reduction occurs at the cathode [pneumonic: red cat]) which corresponds to the positive terminal. In an electrolytic cell (non-spontaneous) the electrons flow to the cathode also, but in this case it is the negative terminal. Electrolytic cells require a power source to force electrons to travel to the negative terminal. Hope that helps.