[mslee]

How would you characterize/describe the cell:

Cd(s) + Ni(OH)₃(s) --> Cd(OH)₂(s) + Ni(OH)₂(s)

My teacher recognized that the stoichiometry is wrong but he just wanted us to figure out how this cell worked in general...

I see that Cd is being oxidized to Cd²⁺ and Ni is being reduced... so Cd is the anode and Ni is the cathode... but how is this physically possible with nothing aqueous?

[mslee]

Anyone any ideas? 
I don't know if this will add any, but my teacher said to think about nicad batteries, and I've searched for it, but it's not helped me any.

Some other hints that my teacher gave here and there that didn't make much sense to me is how nickel will gain electrons and it will physically stick to the nickel solid... and how we can use Pt or graphite as an inert electrode (I don't know why we'd need another solid electrode? we already have too many solids  )... he also said to think about Cd solid with Cd(OH)2 coated around it at one point... and lastly, Ni(OH)3-->Ni(OH)2 + OH-=> the OH has to go into solution, "water is necessary" (I didnt really understand this, since nothing in the rxn is stated as aq... is that because none of those are soluble but water is present in both sides of the rxn?)

[Borek]

Remember: library first, wiki/google second, ask on forums third!

http://en.wikipedia.org/wiki/Nicad_Battery

[mslee]

I don't know if this will add any, but my teacher said to think about nicad batteries, and I've searched for it, but it's not helped me any.

Yeah, I've been to that site. I read through it but I didn't see any information that I found to be particularly helpful... I'm now just thinking that the two electrodes are the Cd solid and Ni(OH)3 solid and there's liquid water that has both of the solid electrodes in a beaker with OH- ions floating around... which then helps form a coat of Cd(OH)2 and Ni(OH)2 on each of the solid electrodes... does that sound like a possible electrochemical cell?