do we have to know the applications of eletrolytic cells?

[Zebra]

down cell etc etc etc.... list goes on...

[homosapiens]

not off by heart, just know the basic principles, like how it's necessary to separate the two electrodes and their reactants/products etc.

[Zebra]

yeah okay, but how though?
say it was a hydrogen fuel cell. what's happening at the electrodes?

[azn_dj]

The logic is that you DONT need to memorize any specific cell, BUT you need the knowledge on how they work in general so if they give you a random cell that you've never heard of, you can do it.

Let's say they pull out the "lemon battery" - you haven't learnt about it in VCE. Some people may have done it as a SAC, but if you haven't, how do you answer the question? Your knowledge of galvanic/electrolytic cells should be good enough to apply to any situation you have never heard of.

[Zebra]

Well, I'm asking HOW.

ARGH, apart from that lemon battery example. can you actually provide me with an application of cell and show me how you deduce half eqs from there?

[Vincezor]

Well, I'm asking HOW.

ARGH, apart from that lemon battery example. can you actually provide me with an application of cell and show me how you deduce half eqs from there?

Usually they give you the overall equation and you can work out the half equations by using oxidation numbers and what not.

For fuel cells (such as the hydrogen or methane one) the combustion reaction will be the overall reaction. The 'fuel' that is being used (Let's say CH4 in this case) will be the reactant at the anode, as it is being 'oxidised' (You'll see in the overall equation). Work through that and you can work out the reactions at the anode+cathode.

Other times they may give you just either cathode or anode reaction (Don't quote me on this, this is based off my memory of exams that I did a while ago) and it will be in a similar style to the one above; you work out the overall equation and the other reaction occurring at the anode.

If you are looking for examples, I'm sure almost every second practice exam you do will have some sort of 'application' of this; Lisachem 2011 (Q2 i think) is the only one I strongly remember there being a question that you are seeking. Furthermore, there are the VCAA exams - I'm pretty sure 08' and 09' have them!

I'm not what else to say... maybe I'll make another post on this if you still need help.
 

[Zebra]

thanks. it would be so great if you could give me a quick tutorial one this knowledge!