galvanic cells

[za]

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i read this dotpoin properly for the first time today



gather and present information on the structure and chemistry of a dry cell or lead-acid cell and evaluate it in comparison to:
- button cell
- fuel cell
- vanadium redox cell
- lithium cell
- liquid junction photovoltaic device (eg the Gratzel cell)
in terms of:
- chemistry
- cost and practicality
- impact on society
- environmental impact




for this dotpoint. do we hav to know each of them. coz i was told that u only hav to know 1 of them. and i truly cbf learning em all.

[mystify]

I can assure you that you only have to know 1 of them. I reckon the silver button cell is the easiest (I.M.O) and the lithium cell i heard is easy too.

[za]

iv already learnt the fuel cell and dry cell

i was going thru some blokes notes today and he had info on all of em.
i just wanted to make sure coz the dotpoint isnt that clear.


thnx

[daemonic666]

Originally Posted by za

iv already learnt the fuel cell and dry cell

i was going thru some blokes notes today and he had info on all of em.
i just wanted to make sure coz the dotpoint isnt that clear.


thnx

i cannot find any of the right info
can anyone help me on this?

[theChemCoach]

i read this dotpoin properly for the first time today
Gather and present information on the structure and chemistry of a dry cell or lead-acid cell and evaluate it in comparison to:
- button cell
- fuel cell
- vanadium redox cell
- lithium cell
- liquid junction photovoltaic device (eg the Gratzel cell)
in terms of:
- chemistry
- cost and practicality
- impact on society
- environmental impact

I would just like to help simplify the task at hand here:
Comparision in terms of

• chemistry: his requires you to indenify the anode, cathode and electrolyte used, and its a good idea to include half- and full equations (not neccessary remember them thou). Also comment on the type of electrochemical cell: is it a galvanic cell? (hence it is NON-RECHAREABLE), e.g dry cell or an electrolytic cell (RECHARGEABLE), eg. lead-acid cell & fuel cell.

• cost & practicality: Is it cheap (dry cell) or expensive (fuel cell, lead-acid cell). Also practicality is a reference to its size and lifespan, For example fuel cells, although expensive have a long life-span (lead-acid approx 10 years, fuel cells even longer), and hence the inital cost is off-set by its long lifespan.

• impact on society: translation: WHAT ARE ITS USES? its impact on society is relative to its uses, e.g. dry-cell batteries created an entire new industry in 'portable electronics', e.g the radio became portable etc. Also button cells, lead to the miniaturization of camera, and also paved the way for wrist watches. this is a big point you can elaborate on.

• impact on the enviroment: this is related to the chemicals used in the anode/cathode/electrolyte, e.g with a lead-acid cell (car battery), lead is present in the anode and cathode and the electrolyte used is conc. sulfuric acid. both chemical pose a very bad threat to the enviroment if not disposed of properly.

You will find information on dry-cells in any HSC textbook or just go to www.chemistrycoach.com.au/Batteries.pdf

Also for information a Fuel Cells, check out
http://auto.howstuffworks.com/fuel-cell.htm

Cheers,
George

...

[ButterflyFish]

i know this is an old topic but im having a lot of touble with finding information on lithium cel and gratzel cell, so i thought id ask here rather than making an new topic. can anyone suggest some good websites or tell me a bit about them, especially environmental impact.

thanks,
georgia

[ButterflyFish]

i found the lithium on but the grazel one is causing me so much stress!! any suggestions anyone?

[Dreamerish*~]

Originally Posted by ButterflyFish

i found the lithium on but the grazel one is causing me so much stress!! any suggestions anyone?

Why don't you choose something simpler like the dry cell or silver oxide cell? In the end it doesn't make a difference, as long as you answer the questions and refer to the areas posted by theChemCoach.

It should be in the Chemistry context 2 or Conquering chemistry, or in any chemistry textbook I presume that's where I got all my information on the batteries

[ButterflyFish]

its an assignment so we have to do all of them

Yeah I looked in my textbook (im not that stupid... lol)... ive got CC2 but it hasnt got enough information.

i especially need the equations at the anode and cathode and i cant find them anywhere

Which ones you need? Maybe I can help you out with some?

[ButterflyFish]

mainly the gratzel equations. I cant find them anywhere, or anything about the chemistry of the cell.

The Gratzel cell is also known as the liquid junction photovoltaic cell

the anode reaction is:
TiO_2(s) + light ---> TiO₂⁺_(s) + e^-

the cathode reaction is:
I_2(aq)+2e^- ---> 2I^-

[ButterflyFish]

I you

I think you just saved my life

lol...

do you know what the electrolyte is?

[Soul Searcher]

Structure:

The Gratzel cell consists of:

The complete networks consist of TiO2, ZnO, Ta2O5, and Nb2O5 particles, which contain pores where a liquid conductor (redox electrolyte) can flow through.

It consists of two sheets of conducting glass (electrodes), one which is a dye-absorbed semiconductor which is highly porous and crystalline, TiO2.
The other is an electrically conducting substrate that is transparent like the other electrode. These electrodes are surrounded by a layer of photosensitive (light absorbing) dye, containing ruthenium ions, where this coats the pores of the solid particles. It also consists of conducting films of Platinum (Pt), a thin layer of potassium iodide (KI) and an electrolyte containing an iodine (I2) solution that separates one electrode from the other.

Hope this helps.

Soul Searcher. Ruser 07'