AQA A2 Chemistry - Born-Haber
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- เผยแพร่เมื่อ 15 มิ.ย. 2014
- This video runs through all of the enthalpy definitions from Unit 5 of the AQA A2 spec as well as the construction of Born-Haber cycles and their calculations.
The video also covers the perfect ionic model.
For everyone doing AQA Chemsitry this year... DONT FORGET TO ADD THE ELECTRONS ON YOUR HABER CYCLES!!!! You need to include them in your haber cycles to get the marks!!
OH MY GOD THANK YOU I WAS SO CONFUSED
Hi what do u mean by this
@@mxhhh_ in case you still don’t know, for first ionisation energy we are removing an electron from Na to get Na+
so the full equation should be written as Na+(g) + 1/2Cl2(g) + e-
how to know we add the right electrons? for example Ca3N2? what do you say?
Please make more videos, you are so helpful and I don't think you understand how much you've helped me with AS. You're amazing.
+Diana Yassine Seriously, thank you so much for all of the comments you have left, Diana. They really do mean a lot.
⁵⁹
Could you please do a video about Transition Metals for A2 ?
I can't tell you how helpful you have been! Especially after finding out our exams have been 'cancelled' this year online learning has been really difficult but your videos are genuinely a lifesaver and have helped me keep going. Thank you!
Gahhhhh you are the best!!! you have helped me immensely over the past 2 years i cant stresss how grateful i am to you and your efforts in making these videos! Not to mention you make chemistry seem fun, definitely need more teachers like you!!!!!!!
Because of the new A-level syllabus and their consequential lack of AS exams, my teachers have decided to teach this straight after Energetics 1 because now they're more flexible with their teaching structure. So for our end-of-year mock exams -- the ones which determine the predicted grade that we provide to our Universities -- we'll have to know a few A2 topics...
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But that doesn't matter, considering Sir Rintoul exists in my life.
+Casio FX-plus To be fair, Born-Haber does come naturally after the "AS" energetics stuff as it's all the same concepts. With the change in exams and the likely move to a linear system in some schools, I can see teaching happening more and more like this. Ultimately I will only have three playlist folders that will contain all of the content for the Physical, Organic and Inorganic sections.
Thank you so much, this is so helpful! I struggle with the maths side of A2 Chemistry so this really helps. Your method of explaining and going through examples is really good. I have subscribed :) please continue making these videos!
Really great video! So clear and simple.
Thank you soooo much for this video!! :D
+Diana Yassine No worries at all :)
Very helpful video thank you a lot! Just a little thing but in exam papers they often penalise you if you don't include the electron lost during first ionisation energy (e.g Mg+ +Cl2 + e-). Apart from that your channel has helped me a lot throughout my revision so thank you again.
Thank you! Learnt more from this lesson than i have all year in school
TheWinDoh soo true..me too
you are amazing! thank you for putting effort into making these videos!
vikiwikinana No problem!
Thank you sir for the time you spent making useful videos.
Can you please make a video on organic synthesis they always ask a question at the end of unit 4 that is worth loads of marks? please!!!
My friend David loves you so much! Thanks for your videos
Thanks, Sir. You explain all the topics so well :)
can you please make a video on transition metals and metal aqua ions- thank you for the amazing work by the way, chemistry wouldn't be the same without you :D
Really useful stuff. Just subscribed keep making more videos!! James from Warrington/England
+Jamesr73564 Thanks, James from Warrington/England. I am Mr Rintoul from England also.
Hi just wondering if you could quickly go over the order of reaction topic?
very helpful video, thank you very much
Thank you so much, this was really helpful!
Hey! can you also look at doing a video on ionic compounds in solution, I think it kinda ties up with born haber. Thx!
You are honestly amazing! I've watched all your AS videos and they helped me so much!Please could you do more A2 vids new spec?
forgetting all the electrons in the cycles pattern
thank you so much for the videos you genius
I still dont get it 😭😭
Does your Chem 5 playlist, 4 videos, include everything in the old chem 5 specification i.e. for re-takers ?? Also, thank you, your videos are so much better than boring textbooks!!
thanks! you’re so much better than my teacher :)
Im starting A2 now. Back onto your vids ahah
Syed Kamal Good to hear!
I got a C grade btw, but I would have got an E without you so thanks
damn 6 years ago life was easy
@@maazahmed2341 bro shut up maaz
Your videos are great help 👍 would you be able to do a video on electrochemical cells- unit 5 of the AQA specifcation?
Are you planning on doing all of unit 5? Im really hoping there is one for transiton metals x
Thankyou very much sir, really helped!
Here the night before the exam lol
can you tell me the equation for enthalpy of hydration and solution
15:15
Is it not lattice formation enthalpy since you're going from Na+ and Cl- around to the NaCl?
Heyy , your videos are sooooooooooooooooooooooooooooooo helpful ! , i was wondering if youd be doing the topic on entropy A2 because that is soo hard D;
Thanks for these amazing videos! I have a quick question though on the last bit, does more covalent character result in stronger bonding? Seeing as how the dissociation AgBr is more endothermic than the ionic model predicted so therefore more energy must be put in?
But in Al2O3 it has a lower melting point than MgO because of its partial covalent character, as opposed to the MgO being purely ionic?
Saif Lund No, ionic bonding is stronger as a result of attraction between positive and negative ions. Na and Ag both have a charge of +1 but the ionic radius of the cations differs and as it depends upon two thing: 1) charge on the ions and 2) radii of the ions the values of lattice dissociation differ. The cation with higher charge to radius ratio will have a higher numerical value of lattice enthalpy.
is this the same for the new a2 spec ?
hey I was wondering if u could do an other chem 5 walkthrough
shout out to 2022 alevel students
Hi, went you ionise the Mg and the Na do you not have to show an electron in the equation? Thanks
+Joe Issa Yeah, you do. That's my bad for not including it. It's a change that I will make this year!
Great! Thank you :)
E Rintoul your videos are unbelievable. papers this year have been okay. 1 was better than 2 and 3 is tommorow
Thank you so much!
Manvir J No problem!
Hi sir. You r amazing. I am sooooo thankful to you. Just one thing at 15:16 we working out the lattice enthalpy of formation but you say that calculation will give us lattice dissociation enthalpy.. i am confused?
would you not have to half the enthalpy change for the atomisation of chlorine at 15:29
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Wanna meet me ? :)
We could all meet for a pint?
@@mohammedashfaqpatel936 Astags bro, have some haya
@@ayesharana9802 you're 3 years a bit too late ..
Mr Rintoul you forgot to put and electron after it is gone through enthalpy ionisation
Super helpful
Do they all happen under standard conditions for the definitions
Sir, can you help me with question 2d within the Jan 2013 paper? I do understand how the answer was derived, just slightly confused on how to rearrange the equation.
Thank you!
Imran Khan I think you're best off trying to get a cycle made. It's hard to describe what it would look like though... You need to use the value of lattice dissociation from the table at the start of the question.
Thank you so much - these videos are so helpful! :) do you know of any other good resources for thermodynamics revision?
_fayeeth Thanks! Well I'm planning on getting more videos done, namely entropy from thermodynamics. BUT, if it's notes you're after, chemrevise.org does a very good selection!
Thankyou so much this video helped loads! Do you have any videos with entropy/ Gibbs free energy and feasibility? 😊
+Jade bradley Uploading as I type!
THAAAAAAAANK YOU SOOOOOOO MUCH!!!!!!!! Amazing man
Thank you for help. The formula for Calculating the enthalpy of lattice formation always confused me
During the 1st atomisation energy of sodium, isn't an electron produced? If so, are we required to write that down in our cycle?
*not produced, sorry, but you understand what I mean.
Is this the same for edexcel AS and A Level, International level..
yea
can I use ur vid for edexcel
Helpful 🙏🏻☺️
do you have a video for periodicity in A2?
+ardy399 Not yet. It's a topic that I really don't like so I'm putting it off as long as possible! It may come one day...
isn't that the easiest?
its very annoying and boring
5:10 do you mean the bond disassociation enthalpy
How do you know which way the arrow points in each of the stages? (up or down)
Jacob Hughes-Hallett Good question!
Each arrow represents a particular type of reaction; enthalpy of lattice formation/dissociation, enthalpy of formation, enthalpy of atomisation etc.
Each of the reactions has an enthalpy change associated with it. That change can either be negative or positive.
The nature of the delta H being a CHANGE in energy tells us whether the energy has gone from higher to lower or vice versa.
In a reaction where energy is released (one we could call exothermic) we would say that the enthalpy change is negative. This is because we have gone from a higher energy to a lesser one. The energy that is lost is what has gone to the surroundings, often giving us an increase in heat e.g. a combustion reaction.
The opposite is true for an endothermic reaction of course.
Now when we apply this logic to the Born-Haber cycles, we must always imagine that the cycle has energy as its y-axis, where lower energy is at the bottom and higher energy is at the top.
That means, when a reaction loses energy and is therefore exothermic and therefore has a negative enthalpy change, we draw the arrow going downwards.
The opposite is true when we look at an endothermic reaction.
Has that helped at all?
Yeah Thanks,
This was my first time learning about Born-Haber cycles, so that has really helped.
Hey, will you continue to make these videos? I don't mind motivating you by donating money for the production of the next video tutorial. I got a B in my AS- and it's all thanks to you.
***** Yeah, certainly going to keep them going until the whole course is covered! Thank you for the offer of money, but that's not necessary!
E Rintoul Thank you so much. Your videos are better than those that I have paid a subscription to!
E Rintoul Firstly, thanks a lot on the awesome videos.
I also wanted to know when you're planning on making new videos?
***** I'm going to try and slowly get them done. The plan is something like 1 a week. It all depends on how busy I am with school!
Hi Mr rintoul. At 21:53 you added the 1st and 2nd ionisation enthalpies of Mg separately. However when I was working out another question involving sodium oxide. I had to simply use only the first ionisation enthalpy and times it by 2 and not add it separately like you have done. Please can you explain when to add the ionisation enthalpies separately like u have done and when to add them all in one.
If you still want to know. You use the 1st and 2nd ionisation energies in different situations. When converting Mg -> Mg+ then its 1st Ionisation Energy and when its Mg+ -> Mg2+ you use the second ionisation energy which is what is happening in this case. For your question its likely that you had to convert either 2 moles of the Sodium Oxide (But that would go against the enthalpy rule) or had to do it for 2 separate molecules.
The way ive never been so confused in my life
On equation 8 ( beginning definitions) you said cl aqueous but on the video it says gas - which one
when sodium changed its physical state from solid to gas .......shouldn't v consider the energy required for sublimation?????
pls reply soon
That's Enthalpy of atomization. Atomization is turning the Sodium solid to gas
I think you meant lattice formation at 15:10
Do you need to show the electrons in the born haber cycle during the ionization step?
my teacher makes us write em out, i think it's safer if you do
I might be wrong but in the first Born-Haber cycle example with NaCl, I don't think the enthalpy of lattice formation (-787 according to the video) worked out is correct as when I substitute that value back in to then work out enthalpy of formation it doesn't equal -411 as given by the table of values. Also, I think the enthalpy of atomisation value for chlorine should've been multiplied by 0.5 to get 1 mole of chlorine. Please correct me if I'm wrong :)
Firstly if you return back to the definitions, the enthalpy of atomisation is "the enthalpy change when 1 mol of gaseous atoms is formed from its element in its defined physical state under standard conditions". This is about the formation of one mole, not one mole of the element forming the gaseous atoms, and therefore there is no need to multiply by 0.5.
Secondly, perhaps you made an error with direction round the cycle and so used the incorrect signs (+/-) when you substituted it back, as it worked when i did it:
+107+122+496-349-787=-411
Hope this helped :)
Hi these videos are so helpful thank you so much Can you make some unit 5 videos on transition metals and titrations of potassium manganate and and also like how you did the chemistry 1 and 2 paper can you do that for a unit 5 paper thanks
say you were asked to find the enthalpy of electron affinity of KCL how would you find it, without being given a haber born cycle, simply given values for the enthalpies
+Vic D You would have to construct a cycle and then go around the cycle in the correct order to find those missing values.
Hi, for the MgCl2 cycle, you said that theoretically speaking, if we were dealing with MgCl (therefore removing 2nd Mg IE) our lattice value would be MORE negative. Wouldn't it be LESS negative? Great job on your videos by the way, if I get an A in chemistry then it's all thanks to you!
Haych M It all depends on whether you are talking about the lattice formation or lattice dissociation enthalpy...
E Rintoul shouldn't the lattic dissociation enthalpy be pointing upwards?
Samiul K he was calculating lattice formation and then converted it to dissociation afterwards
Samiul K What (s)he said...
Fizzy Cokecola Thanks!
yea but what about the 1/2Cl? why haven't you halved the atomisation of Cl?thanks ;)
dan scotfield Hi, Dan! By definition the enthalpy of atomisation is the enthalpy change to produce one mole of atoms from the element in its standard state. Therefore, the process of 1/2 Cl2 --> Cl is an example of this change, therefore no multiple is needed.
In the case of Cl2 --> 2Cl, we would double because we are producing 2 moles of atoms.
Make sense?
i love you man
Good video however i wasnt sure why u went across in the lattice formation?
Karim Saad The going across is just so that there is room to then go down! You have to imagine the whole diagram is set against a y-axis that is going from less energy at the bottom to more energy at the top. With this in mind, a horizontal move doesn't change any energy at all, instead it just gives me a little more room!That helped?
at 8:05 should the Cl be gas or aqueous? you said aqueous but it shows it as gas.
I’m wondering that too I think it’s a mistake and that it is aqueous
at 19:18 isnt it bond dissociation. i dont understand why its atomisation.
+Eliot Rintoul
It depends on the values you are given. If you given bond dissociation then you use that otherwise you use atomisation because it has been provided
yeehaw i actually understand now :,-)
24:00 onwards
Have you got any entropy vids? x x
+kalyna McCool Not yet. I've just taught this again and I think I have a better way of explaining it that I shall attempt to make into a video soon!
Thanks...appreciated
we do not care
Bromine as a liquid as its standard state? I dnt think so...
It is? XD
Hey! At 19:17 you explained that you converted Cl2(g) to 2Cl(g) via enthalpy of atomisation. I understand the need to do this but since enthalpy of atomisation states it must produce one mole of gaseous atoms as a product wouldn't this be wrong as it would produce two moles of gaseous atoms, 2Cl(g),and instead shows bond dissociation enthalpy, breaking of one mole of gaseous bonds forming gaseous atoms? Thanks for the videos, they are really helpful. Please can you correct me if I went wrong!
Robert Wyn you're correct. The value that is given, by definition, is for the formation of one mole of gaseous atoms. However, we need to produce two moles. Therefore we double it.
18:00
at 7:49 you say cl- aqueous, but it's written down as gas :/ confused
Typo
Albert sanchez
Who is that?
What is your @ name?
Hey... Can you make some videos on the colour changes and the catalyst reactions... thnks :)
Sykik doc I will do at some point, but it's more likely that CHEM4 will get finished before a lot of the CHEM5 stuff gets looked at!
Will be done before annual exams ?
It*
Sykik doc I'm hoping that CHEM4 will be done. BUT, I'm doing all of these videos alongside my normal teaching and it's hard to find the time, hence I haven't done one for a while! There will be more coming though!!!
Np.. I can understand :)... tbh you should be paid for doing this on youtube cos its sooo helpful!! Anyway ill be still waiting for your amazing vids!!
i love him lmao
11:33 forgot the state symbol for Chlorine
+nayim hasnain It's a tutorial - not a marked examination. I'm sure we'll survive
+MmmHmm It's a constructive comment. Just because you know its "(g)" doesn't mean everyone does. If copied word for word, its a mark, could be a grade boundary, could be missing a university offer. So one may not survive.
+nayim hasnain That escalated quickly
nayim hasnain Touché, thought you were nitpicking
I can't understand 🙁
c
+Lalay Wayn For real?
I completed an exam paper on thermodynamics following this method of going around the arrows to get to the value of lattice dissociation, turns out I got all marks wrong because this is the wrong method!! You do not need to follow the arrows around but rather WITH. So for example (changing sign to positive) lattice formation + atomisation + ionisation - electron affinity to get to the value of dissociation!! I dont know why he is explaining it like this because I got the answers wrong for EVERY SINGLE QUESTION following this method so annoying having to reteach myself the same thing OVER AND OVER AGAIN
r008x chillll
No homo but I love you
f
+Lalay Wayn Yep.
exam's in 3 hours lol
Hoping you reply to me:)
what
Couldn't understand the writing.
Minahil Farooq apologies.
am I the only one who is failing in as level
Does anyone play fortnite here?
Please... Translate videos for Arabic.
Find someone who speaks English and Arabic and ask them to add subtitles