salt bridges in galvanic cells (1 Viewer)

[punk0rz]

hi im new - just a quick question.
ive look through text books and havent been able to clarify this

what is the purpose of a salt bridge in a galvanic cell?
i know it completes the circuit, but how does it do this? my assumption is:

as electrons leave the anode (oxidising the anode, leaving + ions of the terminal material in solution) and travel to the cathode end (reducing the ions in solution on the cathode end, precipitating them out), more electrons are present in the solution on the cathode end and less at the anode end then there were originally - the ions in the salt bridge even this out by drifting to either side, hence the same ammount of electrons are present either side of the cell as when the reaction began
and since electrons are taken from the anode, negative charge is replaced by anions from the salt bridge and vise versa for cathode?

am i close?? its late and im tired so ive probably messed something up but is that the general idea? im going to bed

 

[ND]

Yep the salt bridge allows the migration of ions.

 

[underthesun]

If you have conquering chemistry I think it said what you just wrote, and there's a main point that said what ND said above.

 

[punk0rz]

hmm

no we use chemistry contexts 2 at my school

ive never heard of that textbook, do u recommend it?

thanks for the help

 

[underthesun]

Not at this stage really..

 

[silbi]

we use chem contexts 2- aswell^^

 

[hipsta_jess]

it allows the ions to flow in between the two cells.

oh, we use both chemistry contexts 2 and conquering chemistry. personally, i prefer conquering chem over chem contexts, it just seems to word things a bit easier. also, look at the hsc chem excel book, and the revise chem core in a month, both are good

 

[~[TaLeC]~]

Conquering chemistry words things better...but chem contexts looks closer at things and can provide more relevant info...
e.g. Chem contexts has stuff on lithium cells, conquering chem doesn't...so if you wanted to make a comparison amongst cells (a common question) then the lithium and dry cells are easier to compare....

In terms of your question...yes you are correct with what your saying...in order to put more relevant wording down in an exam situation, use ND's quote of "allowing the migration of ions"...
This essentially means that there is no buildup of ions in either eltrolyte solution and maintains electroneutrality across the cell...that's just some wording you might want to use...