Former PEM fuel cells engineer here. You did a really good job explaining the principles of Proton-Exchange Membrane fuel cells, and the animation are really clear. Well done! When noting the cathode and anode are in reverse, viewers may find it helpful to know why. Electrolysis is essentially the reverse reaction of a fuel cell. Some (but not all) fuel cells can even be run in reverse to create hydrogen again.
Is it reverse because the hydrogen loose an electron whereas in normal electrolysis the aim is to separate and so normally the hydrogen would already be an ion and the electrolysis would give it the electron it needs to have a full outer shell?
SIr, i have a question, if the electron is seperated from the Hydrogen Atom, wouldn't it be basically a proton, and if so, why is it moving towards the positive electrode and not sticking to the negative electrode. also, what cause the hydrogen atom to loose its electron at the negative anode, are we supplying any kind of energy to the negative anode. I really need to know, thank you
@@wannabeadonis69 look im no expert but what do you mean the electron is essentially a proton? an electron is an electron regardless of whether it's been separated from anything or not. it doesnt change into a proton. the hydrogen atom becomes a positive ion because it has more protons than electron, but the ELECTRON doesn't become a proton..
@@wannabeadonis69 Hi, when a diatomic hydrogen molecule reaches the cell anode, it is ionised (I.e. its electrons are separated, resulting in two loose electrons and two Hydrogen ions (2H+ and 2e-). So yes, in essence the H ion is a proton, but usually appears diatomically (two protons together). This happens as the anode/cathode is actually a thin membrane. The anode side of that membrane is coated with platinum, or a similar material. Platinum is chosen as it is an effective catalyst for hydrogen excitation, and has sufficient "excitation energy" to cause hydrogen ionisation (I.e. release of the electron). Have a read into "hydrogen elctrocatalysis volcano.plots"). The Hydrogen ions are pushed through the membrane to the cathode side due to a pressure differential. The hydrogen gas is under higher pressure than the air/oxygen at the cathode side. The electron follows the electrical circuit amd is attracted to the cathode, due to the presence of positively charged hydrogen ions that have now emerged at the cathode side of the membrane, combining with oxygen to form water.
@@m_148exactly, the hydrogen would already be in ion form in the case of electrolysis, that is, when acids dissociate in water or when salts dissolve in water.
I'm an Australian student and I'm in my final year of high school right now. Your videos have always been so helpful and allowed me to understand complex topics easily. Thank you!
You are amazing THANK YOU. I’ve been reading so many articles on fuel cells trying to figure them out for an independent project but wow no one explained better then you just did.
That adults also need pictures to understand something lucidly was explained in the little prince and you are doing a great job in that aspect.Thank u so much for making me understand this concept so well through pictures.
I love your videos so much and find them infinitely helpful. I am also really enjoying your website with the lessons but I was wondering if all the chemistry lessons could have videos attached so it made it easier to access?
thank you, but im kind of confused, isnt the anode the positve and cathode negative like in electrolysis? please respond :), do i have to know why they are differne for gcse
fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire got it?
@@gulnaz9478 fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire got it?
What is the catalyst? What is it made of and how? In what state is the electrolyte based on KOH? Is it an aqueous solution? Is it in solid condition? Please elaborate.
If you’d like to practise what's covered in this video, check out the lesson on the Cognito platform - cognitoedu.org/coursesubtopic/c2-gcse-aqa-h-t_5.04. The platform’s totally free, and has been built to make learning and revision as easy as possible. The main features are: - Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown. - Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on. - Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like. - A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts. - A comprehensive bank of past exam papers, organised both by year, and also by topic. Amadeus & Tom
Great video, but I have 2 questions: 1. Why does the hydrogen get oxidised by the anode? 2. Why do the hydrogen ions move to the positive cathode when the hydrogen ions are also positive - surely they would repel?
Am I going crazy or aren’t the half equations like this: Anode - O2 + 2H2O + 4e- --> 4OH- Cathode - 2H2 + 4OH- --> 4H2O + 4e- Bitesize says this. I have also seen exam questions say this, but you and various other sources like Seneca say the one in the video. Also your makes much more sense, I don’t know what this other one is about.
why is the anode negative and the cathode positive? and since the charges of anode and cathode are swapped does that mean there is a conventional current/ flow of electrons?
@@shamimmemon1280 fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire got it?
That’s in electrolysis. When it’s redox the anode is negative and the cathode is positive. I do a level chem lol u can take it from me . U have to memorise that
Thank you so much! I was very confused over this and you made it very clear! A question though. You mentioned a catalyst. What element is used specifically as a catalyst?
H² + OH- --> h²O + e- basically hydrogen gas reacts with the negative OH anion forming water however because OH carries a negative charge, it means it has an extra electron which has to be released hence water and electrons are the products.
fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire got it?
Hi Cognito, it seems that the half equations for the fuel cell described are not quite right. If the fuel cell uses KOH, which is probably concentrated, as the electrolyte, the set of half equations should be the ones involving hydroxide ions instead of protons. The half equations that you had in the video are for the fuel cell using acidic electrolyte, say concentrated H2SO4 instead.
Cognito I am A student of Grade 9 Prep for IGCSE Your vid and explanation is really Good so Can you Guide me for Getting good Results in IGCSE If you Can Help me
@@rapesquad I know that the cathode is positive. My question is how comes the H+ (positive ion) moves towards the POSITIVE electrode if like charges are supposed to repel?
@@subbhy3791 i see, well cathode temporarily switches off. during hydrogen moving to the elcyrode. more a-level stuff exams over now anyways! howd u find it?
@@rapesquad oh ok thanks. It was a good paper, some calculations resulted in some questionable values (0.021.. mol/dm^3, 60,000 dm^3) but concurred with what others got!
No because in redox, the anode is negative and the cathode is positive. It’s the other way in electrolysis. I do a level chem and it’s the same thing lmao
Helo, can you please explain a little bit more about the positioning of the positive cathode and the negative anode? In my textbook, it says the opposite, in your video, u said that the negative is on the left side and the positive is on the right side. However, my textbook says that the positive is on the left side and the negative is on the right side. Plss replyy thankssss
2nd question, in your video,you said that the equation for the left cathode,which is the negative anode,is: H2->(2H+) +2e-. However in my textbook, it says “ at the negative electrode: 2H2(g) + 4OH-(aq)-> 4H2O(l)+4e-“. Are both of these equations the same?. In your video, you also said that on the right cathode, positive cathode,the equation is: O2+(4H+)+4e-. However in my textbook, it says “ O2(g)+2H2O(l)+4e-->4OH-(aq)”. Are both of these equations the same? Pls reply 🙏 thank youu
Thank you so much. Really helpful..you saved my whole day. Thanks for your efforts😁.Appreciate it from bottom of my heart 👏🏻👏🏻👏🏻👏🏻.. May God Bless you😇 Subscription :- ✔️
fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire got it?
Former PEM fuel cells engineer here.
You did a really good job explaining the principles of Proton-Exchange Membrane fuel cells, and the animation are really clear. Well done!
When noting the cathode and anode are in reverse, viewers may find it helpful to know why.
Electrolysis is essentially the reverse reaction of a fuel cell. Some (but not all) fuel cells can even be run in reverse to create hydrogen again.
Is it reverse because the hydrogen loose an electron whereas in normal electrolysis the aim is to separate and so normally the hydrogen would already be an ion and the electrolysis would give it the electron it needs to have a full outer shell?
SIr, i have a question, if the electron is seperated from the Hydrogen Atom, wouldn't it be basically a proton, and if so, why is it moving towards the positive electrode and not sticking to the negative electrode. also, what cause the hydrogen atom to loose its electron at the negative anode, are we supplying any kind of energy to the negative anode. I really need to know, thank you
@@wannabeadonis69 look im no expert but what do you mean the electron is essentially a proton? an electron is an electron regardless of whether it's been separated from anything or not. it doesnt change into a proton. the hydrogen atom becomes a positive ion because it has more protons than electron, but the ELECTRON doesn't become a proton..
@@wannabeadonis69 Hi, when a diatomic hydrogen molecule reaches the cell anode, it is ionised (I.e. its electrons are separated, resulting in two loose electrons and two Hydrogen ions (2H+ and 2e-).
So yes, in essence the H ion is a proton, but usually appears diatomically (two protons together).
This happens as the anode/cathode is actually a thin membrane. The anode side of that membrane is coated with platinum, or a similar material. Platinum is chosen as it is an effective catalyst for hydrogen excitation, and has sufficient "excitation energy" to cause hydrogen ionisation (I.e. release of the electron).
Have a read into "hydrogen elctrocatalysis volcano.plots").
The Hydrogen ions are pushed through the membrane to the cathode side due to a pressure differential. The hydrogen gas is under higher pressure than the air/oxygen at the cathode side.
The electron follows the electrical circuit amd is attracted to the cathode, due to the presence of positively charged hydrogen ions that have now emerged at the cathode side of the membrane, combining with oxygen to form water.
@@m_148exactly, the hydrogen would already be in ion form in the case of electrolysis, that is, when acids dissociate in water or when salts dissolve in water.
This guy just saved my IGCSE exams
Keep doing what you're doing. Thank you so much😁
I am literally going to fail chemistry wtf
mood ngl
Same
Man same ;-;
Same
Because our teacher came from Ohio
Your animations are really good and easy to understand
@Alex College I like them tooo
I'm an Australian student and I'm in my final year of high school right now. Your videos have always been so helpful and allowed me to understand complex topics easily. Thank you!
Best of luck!
You are amazing THANK YOU. I’ve been reading so many articles on fuel cells trying to figure them out for an independent project but wow no one explained better then you just did.
i hope that a question from this topic comes up cuz you explained it excellently
i love your animations! for me visual is the best way to understand somthing (i often zone out in free science guys lessons)
Yess same, I am very much a visual learner so reading a textbook is not easy for me but these videos are great
Yea lol the guy in freesciecelessons has a really monotonous look, which just bores me.
night before the exam..
day of the exam..
Hour before the exam…
@@JaydaJKey me too fr
After exam ?😂
Well-made video. Couldn’t understand from the book but this sure helped. Thanks, keep it up. Peace be upon you.
@Ravexnite What
@Ravexnite Bro what 💀
That adults also need pictures to understand something lucidly was explained in the little prince and you are doing a great job in that aspect.Thank u so much for making me understand this concept so well through pictures.
This video helped so much!!! The best part was that they explained how to answer a question if it comes in an exam.
exam in 3 hours and craming in rn
same in 1hr now
I love your videos so much and find them infinitely helpful. I am also really enjoying your website with the lessons but I was wondering if all the chemistry lessons could have videos attached so it made it easier to access?
Saving lives one video at a time
freaking goated man u savin me just before my exam tmr
You really covered up ,what my teacher deliberately ignored ,in the best way! THANKS !
this saved my chemistry grade :o
Thank you so much for this!! One question, though. How does the Hydrogen ions move towards the cathode if both are positively charged?
THAT IS BECAUSE THE CATHODE IS NEGATIVE
WRONG IN THE VIDEO
At 1:45, it is mentioned "negative anode and positive cathode", is it not opposite ?
thank you, but im kind of confused, isnt the anode the positve and cathode negative like in electrolysis? please respond :), do i have to know why they are differne for gcse
Yeah
I'm pretty sure they swap for fuel cells. not sure why, just know that they do.
im the same i came to see if anyone else thought the same in the comments
fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire
got it?
@@gulnaz9478 fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire
got it?
What is the catalyst? What is it made of and how? In what state is the electrolyte based on KOH? Is it an aqueous solution? Is it in solid condition? Please elaborate.
KOH is in liquid state because for ions to gain or lose electrons it needs to be in molten or aqueous state
the catalyst is platinum!!
If you’d like to practise what's covered in this video, check out the lesson on the Cognito platform - cognitoedu.org/coursesubtopic/c2-gcse-aqa-h-t_5.04. The platform’s totally free, and has been built to make learning and revision as easy as possible. The main features are:
- Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown.
- Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on.
- Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like.
- A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts.
- A comprehensive bank of past exam papers, organised both by year, and also by topic.
Amadeus & Tom
Great video, but I have 2 questions:
1. Why does the hydrogen get oxidised by the anode?
2. Why do the hydrogen ions move to the positive cathode when the hydrogen ions are also positive - surely they would repel?
in fuel cells the electrodes are flipped, in electrolysis the anode is positive but in fuel cells it’s negative
I am aware, that's why I said positive cathode
Am I going crazy or aren’t the half equations like this:
Anode - O2 + 2H2O + 4e- --> 4OH-
Cathode - 2H2 + 4OH- --> 4H2O + 4e-
Bitesize says this. I have also seen exam questions say this, but you and various other sources like Seneca say the one in the video. Also your makes much more sense, I don’t know what this other one is about.
Correct I think
What software do you use to make these videos...
why is the anode negative and the cathode positive? and since the charges of anode and cathode are swapped does that mean there is a conventional current/ flow of electrons?
what ive been able to garner is that in fuel cells the names switch
@@zainnajmi4848 why do they switch?
@@shamimmemon1280 because this is chemistry 🥲
@@shamimmemon1280 fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire
got it?
Thnx for explaining fuel cell and u kept it simple and explained it with a ease❤
Best video on youtube :)))
You said negative anode and positive cathode...isnt it supposed to be positive anode and negative cathode?
That’s in electrolysis. When it’s redox the anode is negative and the cathode is positive. I do a level chem lol u can take it from me . U have to memorise that
How th hydrogen can teleport through 2 carbon electrodes and KOH solution?
is this paper one or two in edexcel?
Thank you so much! I was very confused over this and you made it very clear! A question though. You mentioned a catalyst. What element is used specifically as a catalyst?
platinum - it is an inert transition metal
Just wanna say ur channel is amazing
This has helped me so much. Thank you so much
I've seen in some textbooks that the hydrogen has to react with hydroxide to release electrons and water, what's that about?
H² + OH- --> h²O + e-
basically hydrogen gas reacts with the negative OH anion forming water however because OH carries a negative charge, it means it has an extra electron which has to be released hence water and electrons are the products.
Why is chem so hard bruh
please make a vid on how a simple cell works to produce electricity in chemistry
Hello, why are the anodes negative and the cathodes positive in a hydrogen-oxygen fuel cell?
fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire
got it?
perfect explanation, thanks alot
got my chem exam today im actually finnished what is this 😭🙏
Ong
You just cleared my confusion, thanks a lot man!
Ah great, glad we could help Ahmed! 👍
You really deserve more subscribers 💜
Oh thank you!
Amazing! Incredible! Fantastic! Better than Marvel movies!
Hi Cognito, it seems that the half equations for the fuel cell described are not quite right.
If the fuel cell uses KOH, which is probably concentrated, as the electrolyte, the set of half equations should be the ones involving hydroxide ions instead of protons.
The half equations that you had in the video are for the fuel cell using acidic electrolyte, say concentrated H2SO4 instead.
Hi, you can have both acid or alkaline fuel cells, but at GCSE they only do the ones that we cover in the video. At A-level you'll cover both types.
U deserve way more subs bro
Thank you very much for your clear explanation!!
Thanks for explaining this 😊
Cognito has saved so many ppl's GCSE s
Cognito I am A student of Grade 9 Prep for IGCSE Your vid and explanation is really Good so Can you Guide me for Getting good Results in IGCSE If you Can Help me
Yh, I finished my igcse
Got grad 7 and 8 in everything
@@eliteds4200 man that's great
@@eliteds4200 im finishing in 4 days
@@hollowknightshade4208 thanks
how do batteries die?
superb explanation. thank you
1:36 it says cathode is positive and anode is negative,isn't it ather way round?
Nah it’s opposite in fuel cells
skibidi bro , it’s opposite
Helped heaps! Thankyou!
Animation is so aesthetic
Thank you, this helped me a lot!
Can someone explain why the H+ ions move towards the cathode if they are both positively charged? Wouldn’t it just repel?
theyre reversed in fuel cells. so cathodes are positive and vice versa!
@@rapesquad I know that the cathode is positive. My question is how comes the H+ (positive ion) moves towards the POSITIVE electrode if like charges are supposed to repel?
@@subbhy3791 i see, well cathode temporarily switches off. during hydrogen moving to the elcyrode. more a-level stuff
exams over now anyways! howd u find it?
@@rapesquad oh ok thanks. It was a good paper, some calculations resulted in some questionable values (0.021.. mol/dm^3, 60,000 dm^3) but concurred with what others got!
@@subbhy3791 yea lol it was fairly maths heavy. i got 60,000 too
hey, can u pls do cells and batteries?
Bro the Exam is in less than an hope 😭
very educative. thank you regards
Great video gained a great understanding
Bro made a video like I would actually pass dat shit
Skill issue💀😭
Think you made a mistake on the charges of the electrodes, just thought i’d let you know.
💀💀💀💀💀💀
gcse today ty mate
So well done ... thank you
arent cathodes negative and anodes positive?
Exactly
No because in redox, the anode is negative and the cathode is positive. It’s the other way in electrolysis. I do a level chem and it’s the same thing lmao
Does anyone know why hydrogen is oxidized? I though it was a positive ion
It gains oxygen to created H2O. As well as this it losses an electron to form the ion in the first place.
amazing
thanks man you are amazing❤👏
"Hydrogen-Oxygen fuel cell" powered EV sounds promising 👌
What the hell is ts
Nice, thank you Sir.
This topic was extremely difficult to understand before watching this video thanks so much
Glad our video could help you out 👍
This lesson is very good
Thank you
Helo, can you please explain a little bit more about the positioning of the positive cathode and the negative anode? In my textbook, it says the opposite, in your video, u said that the negative is on the left side and the positive is on the right side. However, my textbook says that the positive is on the left side and the negative is on the right side. Plss replyy thankssss
2nd question, in your video,you said that the equation for the left cathode,which is the negative anode,is: H2->(2H+) +2e-. However in my textbook, it says “ at the negative electrode: 2H2(g) + 4OH-(aq)-> 4H2O(l)+4e-“. Are both of these equations the same?.
In your video, you also said that on the right cathode, positive cathode,the equation is: O2+(4H+)+4e-. However in my textbook, it says “ O2(g)+2H2O(l)+4e-->4OH-(aq)”. Are both of these equations the same? Pls reply 🙏 thank youu
Same I'm confused
@@jonathanaliesaputra5075 your one is the overall equation, he just did the one at each electrode
Dennis Mihailov aight2 thxx
it doesn't matter which sides the electrodes are on lol
but arent cathode negetive and anode positive
It changes for both electrochemical and hydrogen fuel cells
did u not watch the video
I liked and subscribed
Easy to understand ?
Literally the easiest to understand
Beautiful
ilyyyyyy
Wouldn’t the postive cathode repels the positive hydrogen ions @cognito
hydrogen gets oxidised therefore becomes negative
@@ajmusoni when it’s oxidised it loses electrons so becomes positive.
My dear, I lovd your video and here I am your new subsciber.
Ah thanks, it's great to have you as a subscriber!! 😊
thank you soooo much!!!!!!
You're welcome!
wish you had more subscribers:/
Aha thank you! All in good time 🤞
Cognito fingers crossed 🤞🏽:)
i love you bro
is this aqa
Thank you so much. Really helpful..you saved my whole day. Thanks for your efforts😁.Appreciate it from bottom of my heart 👏🏻👏🏻👏🏻👏🏻.. May God Bless you😇
Subscription :- ✔️
❤
Why do the hydrogen ions move through the electrolyte, surely they would be repelled by the cathode?
There was a mistake, the hydrogen would not completely enter the cathode, but since oxygen is extremely reactive it would form H2O.
Unique Pines
I'm watching this video 2 minutes before my exam
please do a video on testing for cothodes
GOOD JOB👌😍
This video was really great! Are you going to make a video on normal alkaline cells? Their really confusing
Hey, we’ve not got an alkaline cells video in the pipeline at the moment I’m afraid :(
Anyone know if this is actually on tomorrow’s exam?
if you're doing aqa triple, its a may be assessed topic, so it could come up once (possibly twice) in a short question, but its not a major focus
Oh i see i don't get it 🙋
Huh
You are from?
I thought the cathode is negative and the anode positive
fuel cell is a galvanic cell and in a galvanic cell anode has a negative charge while the cathode has a positive charge but in the case of electrolytic cells the anode has a positive charge and the cathode has a negative charge this change is bcz in electrolytic cells battery is used to provide electric current while In galvanic cells no battery is used and the elements are oxidized (lose electrons) on the anode so the electrons move from anode to cathode through the wire
got it?