What is the purpose of a salt bridge?

[vincikai]

hm... anyone care to tell me "What is the purpose of a salt bridge?" is it the movement of irons, or the transfer of electrons inorder to balance the galvanic cell??? .___.

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[RayhanS1282]

hm... anyone care to tell me "What is the purpose of a salt bridge?" is it the movement of irons, or the transfer of electrons inorder to balance the galvanic cell??? .___.

To allow movement of the ions, i.e. salt bridge of KNO3...K+ moves to the cathode and NO3- to the anode. I think the electrons move acoss the wire.

 

[Medikit]

I think it allows salt people to get over bodies of water. Salt dissolves in water you know.

No seriously, you are losing electrons from one side and gaining them on the other. This would result in a charge inbalance if you didn't have a salt bridge there. In a KCL salt bridge in a galvanic cell one Cl- dissolves per electron lost on the anode side and one K+ dissolves per electron gained on the cathode side.

 

[SpeedRacer]

mmmmmmmmmmmmm...................salt.......

 

[Medinsane]

I actually just reviewed this today. The cations in the salt bridge head towards the cathode (where reduction occurs) cell and the anions head towards the anode (where oxidation occcurs) cell, thus attracting opposite charges and allowing the current to continue in the wire since you don't want all the reduced and oxidized ions to collect in one cell. It's a conduit sort of thing.

 

[wetlightning]

comment: ask these kinds of q's on shrike/QofQuimica/lorelei's beautiful little sub-forum entitled "mcat questions"...they're all 40+'s on the mcat and will have great answers.

not to say that my fellow sdn'ers don't, but S/Q/L are also princeton/kaplan tutors, etc


g'luck all you august mcat'ers!!!

 

[Shrike]

To second, the correct forum for this sort of question is here, and the thread for gen chem questions is here.

By the way, it's true that many of the people answering questions on those threads are instructors for the various test prep companies, but that's not why we're doing it -- we just can, and like to, answer the questions.