GCSE Chemistry - Fuel Cells #45

[@BlindMonk93]

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.

[@m_148]

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?

[@wannabeadonis69]

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

[@ruaaxd]

​@@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..

[@BlindMonk93]

​​@@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.

[@alfred4831]

@@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.

[@jemjem5900]

I am literally going to fail chemistry wtf

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Same

[@mohamedmoayad5138]

Man same ;-;

[@mabo2469]

Same

[@bmn1064]

Because our teacher came from Ohio

[@buditae1658]

This guy just saved my IGCSE exams Keep doing what you're doing. Thank you so much😁

[@gracek695]

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.

[@aaisharahman9883]

Your animations are really good and easy to understand

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[@fatima-pj4jw]

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!

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Best of luck!

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[@IslamicCop]

Well-made video. Couldn’t understand from the book but this sure helped. Thanks, keep it up. Peace be upon you.

[@IslamicCop]

@Ravexnite What

[@IslamicCop]

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[@deca1comania_]

i hope that a question from this topic comes up cuz you explained it excellently

[@nivethaselvam9318]

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Saving lives one video at a time

[@daisysearle3843]

i love your animations! for me visual is the best way to understand somthing (i often zone out in free science guys lessons)

[@robynurquhart2098]

Yess same, I am very much a visual learner so reading a textbook is not easy for me but these videos are great

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[@khadijakhan1941]

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This video helped so much!!! The best part was that they explained how to answer a question if it comes in an exam.

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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?

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Im an aussie student doing the same thing. The animations help SO MUCH

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exam in 3 hours and craming in rn

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[@GG-do8wu]

U deserve way more subs bro

[@LGC996]

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.

[@ogaaa]

Correct I think

[@pranjalchhetri5198]

Best video on youtube :)))

[@ralphgreenwood2195]

Just wanna say ur channel is amazing

[@harsonpakeer7499]

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

[@maristudy5254]

Yeah

[@annabellewhittle55]

I'm pretty sure they swap for fuel cells. not sure why, just know that they do.

[@gulnaz9478]

im the same i came to see if anyone else thought the same in the comments

[@sillyrija2489]

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?

[@sillyrija2489]

@@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?

[@m4897_]

You really deserve more subscribers 💜

[@Cognitoedu]

Oh thank you!

[@kalpavriksha9380]

At 1:45, it is mentioned "negative anode and positive cathode", is it not opposite ?

[@marziyashahwar]

Yeah

[@Akilan.372]

Thnx for explaining fuel cell and u kept it simple and explained it with a ease❤

[@SeemaSalman-qz7mm]

Brother you are doing good for students Keep it up👆 Well all wish you well

[@tanvi.k.8]

Thank you so much for this!! One question, though. How does the Hydrogen ions move towards the cathode if both are positively charged?

[@hoevid19]

THAT IS BECAUSE THE CATHODE IS NEGATIVE WRONG IN THE VIDEO

[@cadenwest1186]

This has helped me so much. Thank you so much

[@mariociencia12]

Amazing! Incredible! Fantastic! Better than Marvel movies!

[@Ozred]

You just cleared my confusion, thanks a lot man!

[@Cognitoedu]

Ah great, glad we could help Ahmed! 👍

[@Imogen_V]

Cognito has saved so many ppl's GCSE s

[@see-yah9823]

please make a vid on how a simple cell works to produce electricity in chemistry

[@arfaamer6234]

Helped heaps! Thankyou!

[@adaam1281]

gcse today ty mate

[@shamimmemon1280]

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?

[@zainnajmi4848]

what ive been able to garner is that in fuel cells the names switch

[@shamimmemon1280]

@@zainnajmi4848 why do they switch?

[@thehalf-bloodprincess2982]

@@shamimmemon1280 because this is chemistry 🥲

[@sillyrija2489]

@@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?

[@vicoltitus9753]

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.

[@mugtoes5333]

KOH is in liquid state because for ions to gain or lose electrons it needs to be in molten or aqueous state

[@ruaaxd]

the catalyst is platinum!!

[@Mcnuggets256]

Great video gained a great understanding

[@aaryanramani1699]

What software do you use to make these videos...

[@aryamaleki4706]

perfect explanation, thanks alot

[@UTHPALA87]

superb explanation. thank you

[@Bajinowhere]

"Hydrogen-Oxygen fuel cell" powered EV sounds promising 👌

[@TV-rf8hq]

Thank you very much for your clear explanation!!

[@naomiparsons462]

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?

[@sdafdsfsdaf]

in fuel cells the electrodes are flipped, in electrolysis the anode is positive but in fuel cells it’s negative

[@naomiparsons462]

I am aware, that's why I said positive cathode

[@juliedahabreh1620]

Hello, why are the anodes negative and the cathodes positive in a hydrogen-oxygen fuel cell?

[@sillyrija2489]

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?

[@dominicchika]

Thanks for explaining this 😊

[@Manoj-z1m7r]

Thank you so much for your help ❤

[@Potatomelon111]

I've seen in some textbooks that the hydrogen has to react with hydroxide to release electrons and water, what's that about?

[@ghostybeware7780]

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.

[@akshayarajarathinam4411]

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?

[@annikashah]

platinum - it is an inert transition metal

[@АрсенийЛитвинчук-к5ю]

1:36 it says cathode is positive and anode is negative,isn't it ather way round?

[@oscarayodele6126]

Nah it’s opposite in fuel cells

[@toshicoshigamez5871]

skibidi bro , it’s opposite

[@clogix6727]

Thank you, this helped me a lot!

[@ShujaRizwan1]

Why is chem so hard bruh

[@yeeyoo3331]

How th hydrogen can teleport through 2 carbon electrodes and KOH solution?

[@shrutijogi677]

Animation is so aesthetic

[@saaddanish8555]

amazing

[@ayubfarah5702]

thanks man you are amazing❤👏

[@seshachary5580]

very educative. thank you regards

[@ericyip3281]

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.

[@Cognitoedu]

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.

[@yes.im.nicholas]

thank you!

[@candicesirju551]

So well done ... thank you

[@life_asthepooh8804]

You said negative anode and positive cathode...isnt it supposed to be positive anode and negative cathode?

[@pinkmangooooo]

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

[@0astr0]

got my chem exam today im actually finnished what is this 😭🙏

[@ogaaa]

Ong

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This lesson is very good

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Nice, thank you Sir.

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@@eliteds4200 im finishing in 4 days

[@eliteds4200]

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[@foddoySS]

is this paper one or two in edexcel?

[@IlTheOnelI]

how do batteries die?

[@bethstephens2088]

Does anyone know why hydrogen is oxidized? I though it was a positive ion

[@amarachiokonkwo3859]

It gains oxygen to created H2O. As well as this it losses an electron to form the ion in the first place.

[@atriumgangsterz1939]

I liked and subscribed

[@l.p.m6716]

This topic was extremely difficult to understand before watching this video thanks so much

[@Cognitoedu]

Glad our video could help you out 👍

[@subbhy3791]

Can someone explain why the H+ ions move towards the cathode if they are both positively charged? Wouldn’t it just repel?

[@rapesquad]

theyre reversed in fuel cells. so cathodes are positive and vice versa!

[@subbhy3791]

@@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?

[@rapesquad]

@@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?

[@subbhy3791]

@@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!

[@rapesquad]

@@subbhy3791 yea lol it was fairly maths heavy. i got 60,000 too

[@MuhammadArif-rb2zo]

Thank you

[@Cognitoedu]

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

[@reillyfleming4411]

Think you made a mistake on the charges of the electrodes, just thought i’d let you know.

[@robloxvibez6613]

💀💀💀💀💀💀

[@jonathanaliesaputra5075]

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

[@jonathanaliesaputra5075]

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

[@mlgpro1963]

Same I'm confused

[@dennismihailov136]

@@jonathanaliesaputra5075 your one is the overall equation, he just did the one at each electrode

[@jonathanaliesaputra5075]

Dennis Mihailov aight2 thxx

[@lipbalm9123]

it doesn't matter which sides the electrodes are on lol

[@Darwizzy_TheGoat9]

Bro made a video like I would actually pass dat shit

[@Sonoroushertz]

Skill issue💀😭

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My dear, I lovd your video and here I am your new subsciber.

[@Cognitoedu]

Ah thanks, it's great to have you as a subscriber!! 😊

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Literally the easiest to understand

[@zainabz6381]

hey, can u pls do cells and batteries?

[@Tsduck27]

Bro the Exam is in less than an hope 😭

[@brutalbomber3721]

Wouldn’t the postive cathode repels the positive hydrogen ions @cognito

[@ajmusoni]

hydrogen gets oxidised therefore becomes negative

[@brutalbomber3721]

@@ajmusoni when it’s oxidised it loses electrons so becomes positive.

[@امانىمنتصر-ض4ق]

Beautiful

[@MotivationalWhisperer]

arent cathodes negative and anodes positive?

[@arooba6807]

Exactly

[@pinkmangooooo]

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

[@toleenahmad7360]

i love you bro

[@lovelyangela2734]

thank you soooo much!!!!!!

[@Cognitoedu]

You're welcome!

[@armitiarmiti1340]

What the hell is ts

[@nasirazahid1811]

but arent cathode negetive and anode positive

[@katiestephen968]

It changes for both electrochemical and hydrogen fuel cells

[@guineapig2478]

did u not watch the video

[@lalaulala8948]

I'm watching this video 2 minutes before my exam

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[@libbyclayton1649]

wish you had more subscribers:/

[@Cognitoedu]

Aha thank you! All in good time 🤞

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Cognito fingers crossed 🤞🏽:)

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is this aqa

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ilyyyyyy

[@YasirUT]

Watching this video while sitting in an exam Hall

[@what_should_i_call_myself4382]

please do a video on testing for cothodes

[@benozen1922]

Why do the hydrogen ions move through the electrolyte, surely they would be repelled by the cathode?

[@plin8344]

There was a mistake, the hydrogen would not completely enter the cathode, but since oxygen is extremely reactive it would form H2O.

[@brutalbomber3721]

I thought the cathode is negative and the anode positive

[@sillyrija2489]

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?

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Unique Pines

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[@ahlrealtors4434]

Easy to understand ?