IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: sh@ni_rox on October 15, 2009, 09:02:10 pm
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hey, cud someone plz explain to me how a hydrogen fuel cell works because i really don't get it... :-[
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Basicall...u must be familiar with the diagram right????
so, there is an electrolyte of NaOH, anode made up of a porous material impregnated with platinum catalyst, and the cathode is made up of a porous material with either cobalt oxide or platinum catalyst. There is an inlet on the anode side for hydrogen and on the cathode side for the oxygen.
Then the reactions are as follows:-
At anode: H2 + 2OH(-) ----> 2H2O + 2e(-)
At cathode: O2 + 4e(-) +2H2O ---->4OH(-)
because, loss and gain of electrons should be same,
therefore,
[ H2 + 2OH(-) ----> 2H2O + 2e(-) ]*2
Which gives us:
2H2 + 4OH(-) --->4H2O + 4e(-)
O2 + 4e(-) + 2H2O ---> 4 OH(-)
from the above two equations, we cancel out 4 e(-) from both side, 2H2O from the equations and 4OH(-) also from the equations
So, we are left with 2H2 + O2 ---->2H2O
the electrons flow to complete the circuit and in this way we also prove the water forming equation.
All understood?????i hope that it helps......
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U ANSWERED UR OWN DOUBT
lol :D :D :D :D
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lol :D :D :D :D
what are u guys talking about>????
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welll heres a ppt ... dat cud explain .. in simple terms ...
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tym_traveller :)
ur ppt consists of the same thing dt i said...just precisely given....lol.....wts d diff man??? :D
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well y r u trying to fight wid me .. wenever i post smthn
i posted it cuz i found it ... nd d info is better organized ... :P
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oho!!!
dude m not trying to fight i was just asking u man....
lol...
y u taking it soo seriously????
just chill man...its all cool!!!! :D
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lol no1 can explain this to me
i had it in grade 10, and mine teacher might have explained it to me more than 20 times, still i dont get the logic ;D
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@vaibhav - lol ... so true
@adi - im nt takin srsly ... everytym this happens .. but chill bro ... lets start afresh ;)
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lol no1 can explain this to me
i had it in grade 10, and mine teacher might have explained it to me more than 20 times, still i dont get the logic ;D
what do u not understand in this vaibhav...
even i was pretty confused when i started off with it bt gradually got it
what do u not understand????i wud want to try to explain!!!
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true dude??
vaibhav whta didnt you understand
the pptis self explaiatory
but By the way
how do we get water at cathode?? it shu be hydrogen i guess!!! ??? ??? ??? ??? ???
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true dude??
vaibhav whta didnt you understand
the pptis self explaiatory
but By the way
how do we get water at cathode?? it shu be hydrogen i guess!!! ??? ??? ??? ??? ???
read my post on this thread....u'll know how water is formed!!
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ohhhk..!!!
so the water firmmed at anode coems to cahhode or something like that??
By the way is it there in IGs or A levels
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yup it comes from the anode!!
it is ig'z dude...its in our syllabus!!!
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wow!!!
i think i read something like hyrdrogen fules for first time in my life!!!
baapre
i guess i must study buy folks
see you day after at sf
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as the working is already clear
these are few advantages for fuel cells
-no pollutants released, only H2O formed.
-produces more energy
-lightweight
-high efficiency
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disadvantages
a constant supply of H2 and O2 is required
generally, H2 is obtained from non-renewable sources. (cracking etc)
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as the working is already clear
these are few advantages for fuel cells
-no pollutants released, only H2O formed.
-produces more energy
-lightweight
-high efficiency
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disadvantages
a constant supply of H2 and O2 is required
generally, H2 is obtained from non-renewable sources. (cracking etc)
u can add to the disadvantages adi:
that it is quite difficult to store hydrogen for use as a fuel
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yea...
thats correct!
By the way..one more for advantages..as u know..for every 4 molecules of water produced 2 are used up at the cathode..
2 molecules are passed throught the porous platinum..and can be used for drinking..
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yup....
bt dude..isn't that only practical for fuel cells used in aircrafts...cuz if v talk about using hydrogen in cars in daily life....do u think this point will count???just a weird question i know......
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yup....
bt dude..isn't that only practical for fuel cells used in aircrafts...cuz if v talk about using hydrogen in cars in daily life....do u think this point will count???just a weird question i know......
in cars...the water can be used as the cooling agent..
there are many other uses for water in car...
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ya rte...i never thought of the coolant ;)
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ohk..bt 1 dout- how dos fuel cell suppy electrical energy aftrall?...juz water is left behind rite??
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ohk..bt 1 dout- how dos fuel cell suppy electrical energy aftrall?...juz water is left behind rite??
wen the electrons flow anode to cathode...movement of electrons = electricity! :P
anode becomes the - terminal
and the cathode = + terminal
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oh k...ohk..gt it
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ohk..bt 1 dout- how dos fuel cell suppy electrical energy aftrall?...juz water is left behind rite??
see my first reply
u'll get it
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Thanksss! :D
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the water in the cars can agin be converted to hydrogen by elctrolising it
andthen that hydrogen cud be used again
is this possible??? ??? ??? ??? ??? ??? ??? ???
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dude.....do u imagine how much energy u will waste to break it down again.....
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I GUESS ELECTROLYSIS OF WATER IS THE MOST EASIEST ELECTROLYSIS EVER DONE!!!!
??? ??? ???
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m not talkinng abt it beng easy or tough....
m saying u'll waste most of the energy produced to electrolyse the water
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thast rite!!
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I GUESS ELECTROLYSIS OF WATER IS THE MOST EASIEST ELECTROLYSIS EVER DONE!!!!
??? ??? ???
but you can't seperate water through electrolysis.. it's a bad conductor rite?
you wuld need an electrolyte such as sulphuric acid to make the reaction start which is a waste i guess..
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yes, electrolysis of pure water is a slow process. using sulfuric acid as the elctrolyte is a waste...
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good suggestion!!
now this idea is folpped!!
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see i told u this just when u gave the idea shrey...but no1 listens to me naa
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i did listen!!
bgut you did not explain dlehddud did!!
so i did not stop arguing!!
By the way stop EADA!!
my ida is flopped!!
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lol soz adi toxic for taking all the credit ><
nd By the way this talk of water going back to hydrogen shuldn't have com up in the first place shuldn't it?
Not sayin dat its bad or nething, bt isnt the whole point of fuel cells using raw materials which is constantly replacable?
So you wouldn't need to seperate water to make hydrogen, it's being constantly supplied... rite..?
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lol...its kk dlehddud....i was just pulling shrey's leg...
and i do agre with u...shudn't have come up....we aere just discussing about the advantages and disadvantages
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lol...its kk dlehddud....i was just pulling shrey's leg...
and i do agre with u...shudn't have come up....we aere just discussing about the advantages and disadvantages
abbe!!
when did ya come to vashi to pull my leg!! :P :P :o :o