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Order of Cell Diagrams

Posted: Sat Mar 02, 2019 2:11 am
by ryanhon2H
I know that in writing a cell diagram, the anode side goes first and then the cathode side goes next. But is there a way to know the order to write the terms of the anode and cathode? Like solids first then aqueous? Or does it not matter?

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 9:01 am
by taline_n
The solid should always come first, then aqueous and gas substances. The solid stands for the anode/cathode, so it should always go on the ends. As for the order of aqueous/gas solutions, I'm not too sure if there's any particular way to write them; Dr. Lavelle hasn't specified so I would think it doesn't matter.

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 9:30 am
by Manu Vohra 1L
Builidng off of the above reponse, just make sure that all aqueous ions are closest to the salt bridge. Also note that if a particular half reaction inlcudes H+ or OH- in it when balanced, you must also include that in the cell diagram on the respective side (anode or cathode depending on which half reaction the H+/OH- came from).

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 4:37 pm
by Luc Lorain 1L
I try to think about it in terms of reactants going to products. For the anode (in some cases, like the Zn/Cu cell) the solid electrode is converted into an aqueous cation. The salt bridge then comes next, to link the anode to the cathode. Then, in the cathode region of the cell, aqueous cations become reduced, forming a solid precipitate along the electrode. Thus, the reaction would be: solid|oxidized cations||cathode ions|reduced solid .

(For reactions that require the platinum electrode, think of the Pt as a bookend for the reaction--either at the very beginning if in the anode, or at the very end for the cathode.)

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 5:06 pm
by Vy Lu 2B
order should be anode - liquids/gases - aqueous species // aqueous species - liquids/gases - cathode.

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 5:58 pm
by Nicole Garrido 2I
Solids always go on the outmost side, furthest from the salt bridge. A TA told me to write the reactant on the left and product on the right. Also aq solutions should be closest to the salt bridge.

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 7:00 pm
by Henry Dudley 1G
Should Pt always be included at the end of the cell diagram. Some textbook questions have answers that don't include a Pt or metal at the end.

Re: Order of Cell Diagrams

Posted: Sat Mar 02, 2019 10:54 pm
by Porus_Karwa_2E
I put in order of the reaction. So for Fe2+ to Fe3+ on the anode side would go in that order.
On the reduction (cathode) we would write in order Fe3+,Fe2+

Re: Order of Cell Diagrams

Posted: Sun Mar 03, 2019 1:23 am
by maldonadojs
Coming from the left, it is solid|g,L|aq.||aq.|L,g|solid

Re: Order of Cell Diagrams

Posted: Sun Mar 03, 2019 1:27 am
by Marcela Udave 1F
Solid|ion||ion|solid

Re: Order of Cell Diagrams

Posted: Sun Mar 03, 2019 4:18 pm
by Ashe Chen 2C
From the left, the order should be Solids|Gas, Liquid|Aqueous solutions||Aqueous solutions|Liquid, Gas|Solids

Re: Order of Cell Diagrams

Posted: Mon Mar 04, 2019 3:18 pm
by Jonny Schindler 1A
Does anyone know when to use a comma in the cell diagrams?

Re: Order of Cell Diagrams

Posted: Sun Mar 10, 2019 7:34 pm
by Abby-Hile-1F
Do you use a comma if there is more than one aqueous species?

Re: Order of Cell Diagrams

Posted: Sun Mar 10, 2019 7:35 pm
by Abby-Hile-1F
How do you know if a reaction requires a platinum electrode?