FUEL CELL HELP

[conl001]

I just realised, i know basically nothing about fuel cells, just wondering if you all think they will be a huge part of the exam and if someone could give me some tips on how to tackle the questions? i.e. in a fuel cell is the anode +ve or -ve?

[Vincezor]

A fuel cell provides a source of energy, so you can think of it like a 'galvanic cell'.

Therefore the cathode is +ve, and the anode is -ve.

Fuel Cells will probably be one of the the 8? questions, as they usually are in recent years + practice exams.

[Panicmode]

Just remember:

- Fuel cells convert chemical energy directly into electrical energy
- Fuel cells require a constant source of fuel to continue discharging
- A fuel cell involving a hydrocarbon undergoes the same reaction as the combustion of that hydrocarbon
- Fuel cells are more efficient than standard combustion reactions (due to energy being converted directly into electrical energy)
- Fuel cells do not show a 100% conversion factor (ie. not all the chemical energy is converted into electrical energy)


That should be enough for the exam. I'm pretty sure they'll be something on them on the exam considering there has been in the past years of the course outline.

[conl001]

cheers guys big help

[Zebra]

if they simply say hydrogen fuel cell. what the heck do they mean?

[geoff_821]

Fuel cells DO NOT RECHARGE.

and Acidic fuel cells are the ones with H+ in the half cell reactions (Acidic = acid = Higher H+ concentration - well thats how I remember it)
therefore alkaline is the 'other one' with the OH- and shit

[HenryP]

if they simply say hydrogen fuel cell. what the heck do they mean?

It means that the main fuel being used at the Anode is Hydrogen gas.

[Zebra]

then how can you deduce half-equations at the electrodes?

this confused me the most. ALSO, what's with alkaline/acidic fuel cells?

[BoredSatan]

then how can you deduce half-equations at the electrodes?

this confused me the most. ALSO, what's with alkaline/acidic fuel cells?

alkaline use OH- in the electrolyte..
so use the water half equation with OH- in it..

for acidic, they use H+ in the electrolyte.
so use the standard hydrogen equation