9.2.4.B3 - different cells plz help!! (1 Viewer)

[mathock]

can anyone give me a brief overview of a dry cell, lead-acid cell and fuel cell?? is it best to put in point form or table?? 10 hours to go

 

[bloodysunday]

Dry cell (Leclanché Cell)

Negative terminal (zinc cylinder): Zn => Zn2+ + 2e-
Positive terminal (carbon rod): NH4+ + MnO2 + H2O + e- => Mn(OH)3 + NH3
Eo = +1.5 V

Lead Acid Cell

Negative (lead rods): Pb + SO4^2- + 2e- => PbSO4 + 2e-
Positive (PbO2 coated lead rods): PbO2 + 4H+ + SO4^2- + 2e- => PbSO4 + 2H2O
Eo = +2.0 V

Fuel cell I dont got, sorry.

 

[CM_Tutor]

Negative (lead rods): Pb + SO4^2- + 2e- => PbSO4 + 2e-

should be

Pb + SO₄^2- ---> PbSO₄ + 2e^-

 

[bloodysunday]

lol, whoopsie. im so full of it

 

[lucyinthehole]

In the fuel cell it is: O2(g) + 2H2O(l) + 4e– → 4OH–(aq)

check out the .zip notes from the resources (the ones in the general section)

 

[mathock]

thanks a bunch, much appreciated

 

[lucyinthehole]

also, check out this for a really clear explanation with diagrams and action clips and stuff

 

[xxxcaixxx]

do we need to memorize these stuff?

 

[CM_Tutor]

You do need the equations. You can be asked to compare a named cell to either the lead-acid or the dry cell (your choice) in terms of chemistry, impact on society, etc. Comparing chemistry is hard without the equations. (Sorry. )

 

[mathock]

lucyinthehole you are a legend u've restored my confidence, thanks

 

[lucyinthehole]

hah, thanks, and it's ok. now if only i could somehow have a moment of enlightment....

 

[Atotoi]

Hahahah, someone's definitely "thread happy".


Oh well good luck hocko.. cya 2moro morn @ 9:10...Rep me too!

 

[mathock]

so now i know WHAT they are, wat about comparisons between dry cell and fuel cell in terms of chemistry, cost and practicality, impact on society and environmental impact??

 

[sig]

I got the dry cell info

Cost and Practicality –
• Inexpensive
• Low current output
• Non Rechargeable but cheap to replace
• Short shelf life
• Leakage problems
Impact on Society –
• First commercially used battery
• Widely used in common low power appliances (watches, portable radios/CD’s); has made appliances portable.
Environmental Impact –
• Non toxic causing little problems to the environment
• Landfill due to non rechargeable nature



I'm doing lithium cell as my other so yeah...

 

[CM_Tutor]

If you are going to do comparisons, it is easier to compare to something other than a fuel cell - for example, silver oxide button cell and dry cell:

Chemistry: oxidation - both use a zinc anode, with both producing zinc(II), but owing to difference in the paste / salt bridge, you get different products - Zn²⁺ for dry cell, ZnO for button cell
reduction - different anodes and markedly different reductions. Manganese(IV) oxide to manganese(III) hydroxide for dry cell, silver(I) oxide to silver for button cell.

Cost and practicality: Dry cell is much cheaper, but also bulkier - important depending on the application (a largish battery is OK for a torch, but not for a digital watch, for example)

etc etc.

 

[lucyinthehole]

general overview (i compared fuel and dry cells)

dry cell = cheapest, easy to store, good for daily use
BUT = non-rechargeable, getting outdated, not a lot of energy produced
impact = first commercial batter, portable source of energy, freed ppl up. envirnomentally pretty nasty - components are heavy metals. disposing of it in landfills is damaging for environment, so hard to dispose of.

fuel cell= rechargeable, but expensive, and needs high temps
impact = long-lasting and used for larger applications, such as energy for remote places
environmentally friendly - only product, if done correctly, is water.

 

[mathock]

wat are the comparisons in environmental impact and impac on society??