Salt bridge

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Guillermo Vega 1H
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Joined: Wed Nov 18, 2015 3:00 am

Salt bridge

Postby Guillermo Vega 1H » Thu Feb 02, 2017 11:14 pm

Why is it that Platinum can be used to conduct a salt bridge? What properties does it have that allow it to do so?

Chem_Mod
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Re: Salt bridge

Postby Chem_Mod » Fri Feb 03, 2017 12:10 am

Platinum is commonly used as an electrode because it is a chemically inert metallic conductor. An electrode allows electrons to flow from the anode to the cathode. The purpose of a salt bridge is not to move electrons, but to allow the flow of ions in order to to maintain charge balance because the electrons are moving from one half cell to another. It is important to use a salt with ions that do not affect the cell reaction, and KCl is a commonly used salt bridge.

Michael Lesgart 1H
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Joined: Wed Sep 21, 2016 2:57 pm

Re: Salt bridge

Postby Michael Lesgart 1H » Sat Feb 04, 2017 12:45 pm

I have a follow up question, what allows for a current to flow: the electrons themselves or the electron movement from anode to cathode? Also, during a redox reaction, does the salt bridge allow for the reaction to occur multiple times so that a continuous charge is being generated?

breinhardt3G
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Joined: Wed Sep 21, 2016 2:56 pm

Re: Salt bridge

Postby breinhardt3G » Sat Feb 04, 2017 2:27 pm

In a galvanic cell the spontaneous redox rxn creates the flow of electricity (which is produced by the flow of electrons from the anode- which is negative due to electron build up- to the cathode- which is positive since it is gaining electrons)

The salt bridge is what joins the halves of the electrochemical cell and allows current to flow from one side to the other (thus it completes the circuit).


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