Hey, I am a human from the future. That is not how it actually works. You see, different situations, environments, and some other stuff contribute to what will ensure the most efficient teaching and learning. In a classroom environment, this teacher could have difficulty sharing the exact same information within the same time frame, with the same voice tone, and with no package loss. haha. Due to it being a video there are no other students to provide distractions and thus increase the duration of the lesson and package LOSS!!!!! dun dun dun. Indeed my friend, sitting alone watching a video and taking notes is not comparable to being in a class with other people. In the same way, you can not compare flashcards with just reading the notes. Both work well, but to what extent, and for who? WHO WHOO .... this reminds me did you know, owls hunt other owls? Maybe we should alert the parliament of owls. haha, owl puns are fun. Do you know what else is fun? Finding out whether we live in a simulation and to find out why our miserable souls have been placed on to the earth, why we are not who we think we are, Why we exist!!!!! AND Why I will never be able to finish all of the game theory and vsauce videos in time for tonight's anime marathon.
I wish my Chemistry teacher was half as good as you, everyone in my class uses your videos for revision/learning. Thank you for all the effort you put into them
Keep doing past exam questions please, I find it unbelievably helpful when you go over them identifying where the marks lie! Thanks for all your videos, amazing work!
You are currently saving me from being failing AS Chemistry all together. I come home after a lesson and just switch your videos on straight away because my teacher teaches me nothing (He thinks he is a million times better at teaching than he actually is). I am constantly getting told I shouldn't be doing Chemistry, but thanks to you I am actually understanding all the content, because I am actually learning and being taught it. I sit on a evening playing you videos with my textbook open as if it was a lesson. (Because I am clearing gathering nothing from my actual lessons.)
+Sophie .Jayne That all sounds like a right hassle. But I'm glad you're coping and finding ways to deal with things. Let me know if there's anything I can help with and keep working hard!
I'm so lucky I have a friend who recommended you to me, I've got two weeks to sort out my grades before my mocks and I might actually do it with these videos, I'm understanding chem so much more already
Seriously thank you so much for these videos, I have been basically teaching myself Chem and I have learned more from your videos in one day then the entire month and a half I have been in school! Thank you!
this is video is very good, had trouble with intermolecular from months. This helped to understand a lot and also had qns discussed . Thanks sir for the video
so easy to understand when you explain chemistry, I cant seem to take it in with my current chemistry teacher you're a great help thank you. I will watch you all the way through my A levels :)
Just a quick observation. In question 1c) I’m pretty sure the strongest intermolecular force would be van fer waals. This is because the molecule will adopt a tetrahedral shape in which the dipoles will cancel out and it won’t be a polar molecule.
Thank you soooo much for your videos. I didnt do so well in my previous exams but for the first time...just looking at your videos I am finally understanding the subject. Thank you very very much :D
than you sooo so too much for your amazing videos I missed a lot of school because I had a lot of tournaments last term but I'm catching up because of your videos... I won the chemistry prize last year and I will credit it to your help as well as my brilliant teacher who unfortunately left our school last term.... thank you so ,much
Amazing video thank you!! Btw it is soooo helpful when you go through the relevant exam questions at the end it really made me fill the gaps in my knowledge!!
Did you make a video on electronegativity?? Since you knew straight away the differences between electronegativity when predicting the hydrogen bonds.. Also for the last question could you have wrote there isn't lone pairs in phosphine or is that wrong? Many thanks.
Your videos are absolutely amazing! I'm understanding chemistry so much more with your explanations.... thank you so much! Also, I was wondering what you mean by the titles of these videos "NEW & OLD SPEC", are you referring to the new 2016 SPEC or does "NEW" mean the 2015 spec? I'm asking because I've realised this video was uploaded on Feb 2015.
Thank you! This was really tough to read about as it requires lots of thought. I tried the exam questions at the end before you give the answers and I got them all right apart from the last one. I mentioned that "Hydrogen bonding only takes place between molecules with partially negative Oxygen, Nitrogen and Fluorine atoms attracted to molecules with partially positive hydrogen atoms" I didn't mention the phosphorus's negativity :s
What a coincidence, just been doing a bit of revision on this exact topic as vdw came up in a u1 exam and I was getting a bit confused, good video as always!
only started my as levels and your videos are great for me, I have fun and learn whilst watching them, only wish that there were these videos for biology aha, thanks very much.
Hi, can you do exam questions at the end of every video please as they are really helpful and can you make a video on electronegativity and which parts of the spec it links to?
sorry im still a bit confused. as in how do you know CCl2F2 had dipole dipole but CH4 is just van der waals. like how can you tell which one does and doenst
+campervan20 I'm not the uploader but hopefully I can help :) What I do is draw out the molecule and then label where the electrons are being most attracted using an arrow. I always go positive to negative. When I'm done, I look at opposite ends of the molecule and if they have separate charges, there is a dipole and hence dipole dipole forces. If not, there's just VdW's.
Haha, it's funny how my AS Chem qualified (somehow) teacher learns from your videos too. He doesn't even know why cinemas have staggered seating. He's probably reading this whilst he's teaching...his mouth how to consume crisps. Nice to see you continuing your videos, keep up the good work.
Sir, when we are finding out the electronegative difference for dipole-dipole ......what is the range for the big difference in electronegativity??? 35:54
Hi, I was just wondering, when at 30:11 in the video, how you identified that there were three lone pairs? Is there a set number of lone pairs for a Fluorine (and Oxygen and Nitrogen) atom or did you use the method from the shapes of molecules video? Or am I wrong in both of those suggestions? Sorry if I'm just being stupid! Thanks in advance, your videos are great!
Matt Grigg Just by looking at the electron configuration for fluorine - using the GCSE model, we can see that there are 7 outer-shell electrons. One of these has to be used for the bonding, leaving 6 which are all lonely. That help?
Thank you for this video I feel I understand however there are definitely gaps in my knowledge.. 1) how do you know if a molecule is electronegative and which one is more than another? and 2) how do you know how many lone pairs a molecule contains?
Are dipole-dipole considered Van Der Waals too? The revision assistance guide (wjec) is treating both dipole-dipole and induced dipole as van Der Waals forces.
One thing on that very last question (why no H-bonds in phosphine). There is a lone pair present, so you might reasonably expect an H-bond. But as you say, despite that, the P-H bond has so little electronegativity (compared, say, to N-H in NH3) that it outweighs everything else. Only 1 mark, I know. But in light of your earlier description of the importance of the lone pair in H-bonding, perhaps worth pointing out here.
As well as an adjacent hydrogen, you also need a highly electronegative atom with a lone pair: oxygen, nitrogen or fluorine. Phosphorus isn't electronegative enough. A little late, but hope that helps! 🙂
+Vanessa Costello Yep. What I've written is 100% correct. The reason is due to the bonding being simple molecular. In this bonding the weak VdW forces play a key role.
You are an amazing teacher!!! I wish you were my chemistry teacher at school!! I understood everything except for the phosphine one. Why can't H-bonding take place with Cl? Chlorine is more electronegative, right? I would be grateful if u could clarify it in the comments
Eliot Rintoul I would absolutely love it if you were to do so. Even if you didn’t want to do every topic, just covering some of the harder AS topics like ‘The Immune System,’ ‘Oxyhemoglobin dissociation curves’ ‘Digestion of Lipids’ and ‘The Sodium Potassium Pump’ it would really help a lot of students! :)
34:26 can you say that iodine has a bigger atomic radius than fluorine and therefore has more electrons and so requires more energy to break vdW’s forces ? Rather than saying that iodine is bigger ? Does it mean the same thing and will it get you the marks ?
Just to make sure, do the examiners allow the use of the three dots for a shorter way to say therefore? By the way these videos are really helping me out thanks a lot for your effort.
Thanks, You're videos are amazing but i was just wondering about a few things. at 26:30 do HI, HBr and HCl have dipole-dipole bonding? Also at 31:36 would you talk about bonding (i.e. covalent bonding) because the question says in terms of bonding or can this also mean hydrogen bonding?
For question 1 (c) - I thought the dipoles would cancel because the shape is tetrahedral (four delta negative halides are surrounding the carbon atom? And therefore van der Waals are the only intermolecular forces present? I could be completely wrong though.
I am really stuck on this aspect of dipole dipole molecules. Basically, our teacher said that sometimes the delta postitve and delta negative bonds can cancel each other out, and so even if a molecule has permanent dipole bonds, it may not be a polar molecule overall, and will have no charge. Such as C02. I don't understand when these charges cancel each other out?! And I don't think you covered that in this video. The first exam question you did, you said the strongest force was the dipole dipole force, but wouldn't the charges just cancel each other out on that molecule. Sorry for the long question, and if I sound stupid but I would really appreciate it if you could help me out. Thanks
+Amy Yeah, I just had this very conversation with my Lower 6th group the other day. The video isn't as heavy on polarity and electronegativity as it maybe should be, but I am going to be making changes to the videos over the next little while to break them down into more manageable chunks! The way I explained it was that in some molecules, we have polar bonds. In a molecule such as HCl, the bond is polar. This molecule is also polar and therefore has a permanent dipole. Whereas, in a molecule such as CCl4 (methane with each hydrogen replaced by a chlorine atom), the C-Cl bonds are all polar, but basically the partial charges are balanced throughout the molecule and therefore cancel each other, leading to no permanent dipole. If you look at the shapes of the CCl4 molecule, you will see that it has some kind of symmetry and no matter which way you turn it, it is basically the same molecule. I should say at this point that a permanent dipole comes from an uneven balance in a molecule (or what I described as the molecule being wonky). Using the CCl4 example, but swapping one of the chlorine atoms for a hydrogen to go CHCl3, we still have 3 polar C-Cl bonds, but because of the introduction of the hydrogen atom, we find that the over molecule is now not balanced in terms of its charge. This is because the C-H bond is NOT polar and so the whole thing becomes wonky and as such, we DO have a permanent dipole. Has that helped at all?!
E Rintoul Yes, this is really helpful thank you, I totally get why molecules can and can't be polar. So wouldn't that mean in the CCl2F2 in the first exam question you did, due to all the negative charges around the outside, wouldn't the charges cancel and so there would be no dipole-diple intermolecular forces? And so the strongest would be VDW?
Amy That's a little bit more of a tricky example as the chlorine and fluorine atoms have different electronegativities which would cause the bonds between them and the carbon to be different in terms of their polarity!
hi, recently I discovered ur channel and I must say that I am loving it. but I find it difficult to watch a full 30 to 40 minute videos so would it be possible for u to cut it down in sub topics?? thanks once again 😁😁
+Krupali Parikh I've cut some down into smaller topics. I am aiming to cut others down, but I don't know when I'll get around to it. My advice would be to just watch a small portion at a time!
34:10 - surely the increased size in the iodine atom leads to more/stronger VdW forces between molecules which needs a larger amount of energy to break the bond? I don't understand why you mentioned electrons?
Yo Mr Rintoul, One thing that tripped me up was the H2S, H2Se, H2Te graph. These molecules have permanent dipoles and hence dipole-dipole forces right? So why do we have to talk about the VDW forces?? Thanks in advance
***** Alright, chap? Nope, no permanent dipoles there. You're best to think of permanent dipoles occurring only where we have halogens involved. That help?
Hey, thanks for the video. Would you be able to go over electro negativity at some point? And also, if you have time, perhaps mention solubility and how it links in with hydrogen bonding. My textbooks aren't doing the best job at explaining these concepts to me, and honestly your videos are the only reason I'm still maintaining an 'A' grade in mocks. Thanks.
one question- why does the electronegativity change in iodine molecule ..resulting in induced dipole? what causes this difference in one side of the bond being more positive and the other more negative??
+mehru nisa I think I'm going to redo a lot of the video and break them down into more manageable chunks, the polarity stuff being one of them. BUT, until then, don't panic. The easiest thing to think is that the halogens are VERY electronegative and when bonded to carbon or hydrogen, they create polar bonds due to the differences in electronegativity. If we have these permanent dipoles, we have dipole-dipole forces! Does that make sense?
If unsaturated fats are liquid at room temperature due to their shape causing them to have weaker VDW forces, then where does the part about double bonds come in? Wouldn't it make more sense if they were solids at room temp because breaking double bonds requires more energy than single bonds? How do they have double bonds if the VDW are weaker and the bonds are easier to break than saturated single bonded fats?
+Mina Siu there isnt really a difference, its just the difference in electro negativity between hydrogen and F,O and N are so big that they have a different name.
+Mina Siu The dipole-dipole occurs when the electronegativity difference is big enough to allow for it (can't think of the value off the top of my head). H-bonding is similar in that it involves a big electronegativity difference between the O/N/F and H, but it has to involve O/N/F and H.
at 21:65, in the HF example wouldn't there have been 3 lone pairs of bonding electrons around F. And also in H bonding, is the delta -ve delta +ve attraction the reason of H bonding or is it the attraction between delta +ve and the negatively charged bonding electrons? Thanks!
Just outta curiosity do you reckon you can give a link in the description of AQA exam past questions specific to the video? E.g in this case a question on Intermolecular Forces? :) Your vids are really helpful btw
The students you teach are so bloody lucky to have you as a teacher
+IshyB135 I'm not convinced they would agree... but thank you for the kind words!
+E Rintoul lol wait till they get their results then I'm sure they will :)
Oie 1 mahina agadi ko chem test ko lagi padira?
lmao
Hey, I am a human from the future. That is not how it actually works. You see, different situations, environments, and some other stuff contribute to what will ensure the most efficient teaching and learning. In a classroom environment, this teacher could have difficulty sharing the exact same information within the same time frame, with the same voice tone, and with no package loss. haha. Due to it being a video there are no other students to provide distractions and thus increase the duration of the lesson and package LOSS!!!!! dun dun dun. Indeed my friend, sitting alone watching a video and taking notes is not comparable to being in a class with other people. In the same way, you can not compare flashcards with just reading the notes. Both work well, but to what extent, and for who? WHO WHOO .... this reminds me did you know, owls hunt other owls? Maybe we should alert the parliament of owls. haha, owl puns are fun. Do you know what else is fun? Finding out whether we live in a simulation and to find out why our miserable souls have been placed on to the earth, why we are not who we think we are, Why we exist!!!!! AND Why I will never be able to finish all of the game theory and vsauce videos in time for tonight's anime marathon.
@@giornogiovanna3139 thanks for your words of wisdom Giorno 👍
You are actually going to save my AS grade
+Ijaz Sultan Haha that's not at all true but thank you nonetheless!
+Ijaz Sultan SAME
tea.
who's watching this legendary youtuber a day before the exam?
me but its in two days 🥲
I wish my Chemistry teacher was half as good as you, everyone in my class uses your videos for revision/learning. Thank you for all the effort you put into them
Keep doing past exam questions please, I find it unbelievably helpful when you go over them identifying where the marks lie!
Thanks for all your videos, amazing work!
+Max Raven I certainly shall do! And thank you for the kind words!
Video was made when I started year 7 now watching this in year 12 prepping for UCAS exams... time flies
Wish we had teachers like you here sir! You work help us a lot. Please never stop
You are currently saving me from being failing AS Chemistry all together. I come home after a lesson and just switch your videos on straight away because my teacher teaches me nothing (He thinks he is a million times better at teaching than he actually is). I am constantly getting told I shouldn't be doing Chemistry, but thanks to you I am actually understanding all the content, because I am actually learning and being taught it. I sit on a evening playing you videos with my textbook open as if it was a lesson. (Because I am clearing gathering nothing from my actual lessons.)
+Sophie .Jayne That all sounds like a right hassle. But I'm glad you're coping and finding ways to deal with things. Let me know if there's anything I can help with and keep working hard!
hi, how did your chem exam go
when u attempt past papers and apply the knowledge, it helps sooooooooooo much
your videos are so so amazing!! They're keeping me going strong through A-Level chemistry, thank you!!
+niamh_violet I'm very glad, Niamh!
Wow, understood all of it! Thanks so much you are a savior! Your students are hella lucky.
You explain these in such a simple but understanding way
I'm so lucky I have a friend who recommended you to me, I've got two weeks to sort out my grades before my mocks and I might actually do it with these videos, I'm understanding chem so much more already
Seriously thank you so much for these videos, I have been basically teaching myself Chem and I have learned more from your videos in one day then the entire month and a half I have been in school! Thank you!
this is video is very good, had trouble with intermolecular from months. This helped to understand a lot and also had qns discussed . Thanks sir for the video
so easy to understand when you explain chemistry, I cant seem to take it in with my current chemistry teacher you're a great help thank you. I will watch you all the way through my A levels :)
Just a quick observation. In question 1c) I’m pretty sure the strongest intermolecular force would be van fer waals. This is because the molecule will adopt a tetrahedral shape in which the dipoles will cancel out and it won’t be a polar molecule.
Nah Ra is Radium :)
The graph should say Rn.
Good luck in the exam tomorrow, everyone!
I loved this video so much! Honestly, it helped me loads and made this topic super fun and easy to understand finally! Total game changer - very happy
You are such a good teacher. Thank you for enlightening us with your knowledge
Thank you soooo much for your videos. I didnt do so well in my previous exams but for the first time...just looking at your videos I am finally understanding the subject. Thank you very very much :D
than you sooo so too much for your amazing videos
I missed a lot of school because I had a lot of tournaments last term but I'm catching up because of your videos... I won the chemistry prize last year and I will credit it to your help as well as my brilliant teacher who unfortunately left our school last term.... thank you so ,much
Thank you so much. Your clips really help. You might actually save my as grade in chemistry.
Thanks again 😊👌👌😊😊😊😊😊😊😀😀😀
always saw ppl commenting these but here i am, wathing this a day before my as paper. feel like giving up but this man is keeping me going
So how was the paper ?
Amazing video thank you!! Btw it is soooo helpful when you go through the relevant exam questions at the end it really made me fill the gaps in my knowledge!!
This is brilliant, clear and easy to follow explanations ...finally I understand intermolecular forces. Thank you so much!
Did you make a video on electronegativity?? Since you knew straight away the differences between electronegativity when predicting the hydrogen bonds.. Also for the last question could you have wrote there isn't lone pairs in phosphine or is that wrong? Many thanks.
3 years ago!!!!!!!!!!!!!! What grade did you get?
@@edwardjarvis3442 lol r u doing AS now hahahaaaa
Muna Ali yeahh why
@@edwardjarvis3442 so you are now doing A2 good luck man
your videos are genuinely awesome I don't usually comment much but have to here bc they are so helpful! plz keep doing them!
Your videos are absolutely amazing! I'm understanding chemistry so much more with your explanations.... thank you so much! Also, I was wondering what you mean by the titles of these videos "NEW & OLD SPEC", are you referring to the new 2016 SPEC or does "NEW" mean the 2015 spec? I'm asking because I've realised this video was uploaded on Feb 2015.
A-level is going to be so easy.. now I have found this RUclips channel
You are an awesome teacher and it's not relevant, but I like your handwriting. Keep going with your good work!
Thank you! This was really tough to read about as it requires lots of thought. I tried the exam questions at the end before you give the answers and I got them all right apart from the last one. I mentioned that "Hydrogen bonding only takes place between molecules with partially negative Oxygen, Nitrogen and Fluorine atoms attracted to molecules with partially positive hydrogen atoms" I didn't mention the phosphorus's negativity :s
Boro Jen xX Good work!
THANK YOU sir for the effort and time you put into your videos
I'm in love with A-Level Chemistry Mr Ritnoul. Cheers :)
My exam is tomorrow, it’s 2am now, I’m cramming everything and your video was AMAZING..
this was just fabulous hope there r videos on all AS A level topics
+peter sameh I love the word fabulous. Thank you for using it.
I actually love you, and this subject... Great videos thank you! :)
+galefray Galefray, we barely know each other. But thanks.
@@MrERintoul people are just being thankful so just thank them instead of saying u don’t know them
@@zlayer_115 Lmao relax, he was just kidding.
@@galefray oh my b bruh
What a coincidence, just been doing a bit of revision on this exact topic as vdw came up in a u1 exam and I was getting a bit confused, good video as always!
Matthew Cooper A good coincidence indeed! Thanks!
I wish I had found these videos earlier because they are so helpful! Kinda too late now but last minute cramming as my exams tomorrow!
Thank you so much your videos are soooooooooo helpful! God bless you.
only started my as levels and your videos are great for me, I have fun and learn whilst watching them, only wish that there were these videos for biology aha, thanks very much.
+Rega Ali I've considered doing some Biology videos... Maybe in the future!
+Rega Ali And thank you for the kind words :)
+E Rintoul yeah if u could do biology videos it would be great but for now these chemistry ones are brilliant
Really great video! Love your no nonsense approach and the way you go through the exam questions is very useful. Thanks! :)
Hi, can you do exam questions at the end of every video please as they are really helpful and can you make a video on electronegativity and which parts of the spec it links to?
Your videos help me so much lad, my teacher’s a mess I swear. Thanks a pile hie
Thank you so much, your videos are always a huge help!
Kate Clarke No problem at all, Kate!
sorry im still a bit confused. as in how do you know CCl2F2 had dipole dipole but CH4 is just van der waals. like how can you tell which one does and doenst
+campervan20 I'm not the uploader but hopefully I can help :) What I do is draw out the molecule and then label where the electrons are being most attracted using an arrow. I always go positive to negative. When I'm done, I look at opposite ends of the molecule and if they have separate charges, there is a dipole and hence dipole dipole forces. If not, there's just VdW's.
for question 1c) ccl2f2 wouldnt it be symmetrical so therefore nonpolar?
Thank you my dude. Glad I found your channel.
Haha, it's funny how my AS Chem qualified (somehow) teacher learns from your videos too. He doesn't even know why cinemas have staggered seating. He's probably reading this whilst he's teaching...his mouth how to consume crisps.
Nice to see you continuing your videos, keep up the good work.
Twenny Wan I'm sure your teacher means well! But thanks for the kind words!
for question 1e) at 32:30, can you mention F2 is monoatomic and therefore will have weak van de walls due to its small molecular size
quick question. why can’t it be hydrogen bonding with something other than N,O,F that is electronegative
I love your videos
You are so helpful
Thank you for your effort!
You my friend are AMAZING,
+Faisal Hussain Thanks, Faisal!
every one has already said this but man you are a god send thanks a lot best teacher i have ever come across and that's through a video XD
Hello,
May I know why the hell does CCl2F2 have dipole-dipole forces? Thanks! :D
Thanks alot bless up am rilly getting 🙏
Sir, when we are finding out the electronegative difference for dipole-dipole ......what is the range for the big difference in electronegativity??? 35:54
Hi,
I was just wondering, when at 30:11 in the video, how you identified that there were three lone pairs? Is there a set number of lone pairs for a Fluorine (and Oxygen and Nitrogen) atom or did you use the method from the shapes of molecules video? Or am I wrong in both of those suggestions? Sorry if I'm just being stupid!
Thanks in advance, your videos are great!
Matt Grigg Just by looking at the electron configuration for fluorine - using the GCSE model, we can see that there are 7 outer-shell electrons. One of these has to be used for the bonding, leaving 6 which are all lonely. That help?
Yes, it helps a lot!
Thanks for replying :)
Excellent Video ! Helped me alot, Thank You.
Umer Khan Spot on - glad it was of some help!
thank you so much, love the question solving part. Brilliant way to teach!
This was very helpful thank you so much
Thank you for this video I feel I understand however there are definitely gaps in my knowledge.. 1) how do you know if a molecule is electronegative and which one is more than another? and 2) how do you know how many lone pairs a molecule contains?
Can you please do a video going over the Electrochemical cells topic from the A2 spec please?
Are dipole-dipole considered Van Der Waals too? The revision assistance guide (wjec) is treating both dipole-dipole and induced dipole as van Der Waals forces.
how can we know that a specific molecule has enough difference in electronegativity?
One thing on that very last question (why no H-bonds in phosphine).
There is a lone pair present, so you might reasonably expect an H-bond. But as you say, despite that, the P-H bond has so little electronegativity (compared, say, to N-H in NH3) that it outweighs everything else.
Only 1 mark, I know. But in light of your earlier description of the importance of the lone pair in H-bonding, perhaps worth pointing out here.
Dont think hes gonna reply m8
As well as an adjacent hydrogen, you also need a highly electronegative atom with a lone pair: oxygen, nitrogen or fluorine. Phosphorus isn't electronegative enough. A little late, but hope that helps! 🙂
32:30, bonding? What you stated was an intermolecular force, is that right or I'm missing something here?
+Vanessa Costello Yep. What I've written is 100% correct. The reason is due to the bonding being simple molecular. In this bonding the weak VdW forces play a key role.
You are an amazing teacher!!! I wish you were my chemistry teacher at school!! I understood everything except for the phosphine one. Why can't H-bonding take place with Cl? Chlorine is more electronegative, right? I would be grateful if u could clarify it in the comments
The way you talked about Dnaa and replication in this, you should consider making biology videos!
+Glitterfm2133 It's something that I've toyed with, and I used to teach AS Biology as well, but I don't know...
+E Rintoul PLEAAAAAASE DOOOO
Eliot Rintoul I would absolutely love it if you were to do so. Even if you didn’t want to do every topic, just covering some of the harder AS topics like ‘The Immune System,’ ‘Oxyhemoglobin dissociation curves’ ‘Digestion of Lipids’ and ‘The Sodium Potassium Pump’ it would really help a lot of students! :)
at minute 9:07 the symbol for radon is meant to be Rn
+Yas K Yep. It's an image I used from Google though, so don't shoot the messenger!
34:26 can you say that iodine has a bigger atomic radius than fluorine and therefore has more electrons and so requires more energy to break vdW’s forces ? Rather than saying that iodine is bigger ? Does it mean the same thing and will it get you the marks ?
Let’s go dude cuz of you I got A* in chemistry
yes!!!! i understood thank you very much for this vdeo kpt up
+Pradeep Dc Excellent! Well done :)
Just to make sure, do the examiners allow the use of the three dots for a shorter way to say therefore? By the way these videos are really helping me out thanks a lot for your effort.
+FXRain Yeah for real! I love me some 3 dots.
Defintion of electronegative? It might've been in the video but I've watched it in parts thanks.
Thanks, You're videos are amazing but i was just wondering about a few things. at 26:30 do HI, HBr and HCl have dipole-dipole bonding? Also at 31:36 would you talk about bonding (i.e. covalent bonding) because the question says in terms of bonding or can this also mean hydrogen bonding?
For question 1 (c) - I thought the dipoles would cancel because the shape is tetrahedral (four delta negative halides are surrounding the carbon atom? And therefore van der Waals are the only intermolecular forces present? I could be completely wrong though.
why are unsaturated fats branched? something to do with double bonds? i mean they could very well be straight chained, right?
I am really stuck on this aspect of dipole dipole molecules.
Basically, our teacher said that sometimes the delta postitve and delta negative bonds can cancel each other out, and so even if a molecule has permanent dipole bonds, it may not be a polar molecule overall, and will have no charge. Such as C02. I don't understand when these charges cancel each other out?! And I don't think you covered that in this video.
The first exam question you did, you said the strongest force was the dipole dipole force, but wouldn't the charges just cancel each other out on that molecule. Sorry for the long question, and if I sound stupid but I would really appreciate it if you could help me out. Thanks
+Amy Yeah, I just had this very conversation with my Lower 6th group the other day. The video isn't as heavy on polarity and electronegativity as it maybe should be, but I am going to be making changes to the videos over the next little while to break them down into more manageable chunks!
The way I explained it was that in some molecules, we have polar bonds. In a molecule such as HCl, the bond is polar. This molecule is also polar and therefore has a permanent dipole. Whereas, in a molecule such as CCl4 (methane with each hydrogen replaced by a chlorine atom), the C-Cl bonds are all polar, but basically the partial charges are balanced throughout the molecule and therefore cancel each other, leading to no permanent dipole. If you look at the shapes of the CCl4 molecule, you will see that it has some kind of symmetry and no matter which way you turn it, it is basically the same molecule.
I should say at this point that a permanent dipole comes from an uneven balance in a molecule (or what I described as the molecule being wonky).
Using the CCl4 example, but swapping one of the chlorine atoms for a hydrogen to go CHCl3, we still have 3 polar C-Cl bonds, but because of the introduction of the hydrogen atom, we find that the over molecule is now not balanced in terms of its charge. This is because the C-H bond is NOT polar and so the whole thing becomes wonky and as such, we DO have a permanent dipole.
Has that helped at all?!
E Rintoul Yes, this is really helpful thank you, I totally get why molecules can and can't be polar. So wouldn't that mean in the CCl2F2 in the first exam question you did, due to all the negative charges around the outside, wouldn't the charges cancel and so there would be no dipole-diple intermolecular forces? And so the strongest would be VDW?
Amy That's a little bit more of a tricky example as the chlorine and fluorine atoms have different electronegativities which would cause the bonds between them and the carbon to be different in terms of their polarity!
E Rintoul Ok I think I understand it now, thank you so much for your help!!!
thank you so much for your amazing videos!! could you please do a video on bonding? it would be a lot of help!:)
Thank you so much for making these videos!! Your explanations are so clear and easy to understand :)
hi, recently I discovered ur channel and I must say that I am loving it. but I find it difficult to watch a full 30 to 40 minute videos so would it be possible for u to cut it down in sub topics??
thanks once again 😁😁
+Krupali Parikh I've cut some down into smaller topics. I am aiming to cut others down, but I don't know when I'll get around to it. My advice would be to just watch a small portion at a time!
34:10 - surely the increased size in the iodine atom leads to more/stronger VdW forces between molecules which needs a larger amount of energy to break the bond? I don't understand why you mentioned electrons?
Yo Mr Rintoul,
One thing that tripped me up was the H2S, H2Se, H2Te graph.
These molecules have permanent dipoles and hence dipole-dipole forces right?
So why do we have to talk about the VDW forces??
Thanks in advance
***** Alright, chap? Nope, no permanent dipoles there. You're best to think of permanent dipoles occurring only where we have halogens involved. That help?
U Mad when you
Hey, thanks for the video.
Would you be able to go over electro negativity at some point? And also, if you have time, perhaps mention solubility and how it links in with hydrogen bonding. My textbooks aren't doing the best job at explaining these concepts to me, and honestly your videos are the only reason I'm still maintaining an 'A' grade in mocks.
Thanks.
+Casio FX-plus I shall certainly try to. I thought I had actually done a video on electronegativity but maybe I'm just getting confused!
you are incredible. thank you
That's very clear bro. Thank you so much
one question- why does the electronegativity change in iodine molecule ..resulting in induced dipole? what causes this difference in one side of the bond being more positive and the other more negative??
It is completely random
couldn't have said it better! 👏🏼
how do i determine whether a molecule has dipole dipole forces and how do i determine the electronegativities of the elements? thank you :)
+mehru nisa I think I'm going to redo a lot of the video and break them down into more manageable chunks, the polarity stuff being one of them. BUT, until then, don't panic. The easiest thing to think is that the halogens are VERY electronegative and when bonded to carbon or hydrogen, they create polar bonds due to the differences in electronegativity. If we have these permanent dipoles, we have dipole-dipole forces! Does that make sense?
For question 1c why is the answer not vdw forces? The molecule is symmetrical, so it is non-polar and so no permanent dipoles?
If unsaturated fats are liquid at room temperature due to their shape causing them to have weaker VDW forces, then where does the part about double bonds come in? Wouldn't it make more sense if they were solids at room temp because breaking double bonds requires more energy than single bonds? How do they have double bonds if the VDW are weaker and the bonds are easier to break than saturated single bonded fats?
Please can you do a video on mechanisms btw I'm so confused ahh
What is the difference between H bonding and Dipole dipole? Is H bonding only for atoms that are electronegative with lone pairs?
+Mina Siu there isnt really a difference, its just the difference in electro negativity between hydrogen and F,O and N are so big that they have a different name.
+Mina Siu The dipole-dipole occurs when the electronegativity difference is big enough to allow for it (can't think of the value off the top of my head). H-bonding is similar in that it involves a big electronegativity difference between the O/N/F and H, but it has to involve O/N/F and H.
at 21:65, in the HF example wouldn't there have been 3 lone pairs of bonding electrons around F. And also in H bonding, is the delta -ve delta +ve attraction the reason of H bonding or is it the attraction between delta +ve and the negatively charged bonding electrons? Thanks!
+Painus Studios Oh you corrected yourself but still pls answer my question on h-bonding.
+Painus Studios It's the delta positive hydrogen being attracted to the lone pair on N, O or F.
Please make more videos on A2 unit 5
Shumon Miah I've got an entropy one that I want to get recorded soon... watch this space!
Shouldn't the Hydrogen bond be aligned with the lone pair and covalent bond?
+Khalil Jiwa Should it?
+E Rintoul loooooool rintoul did u dirty there
Just outta curiosity do you reckon you can give a link in the description of AQA exam past questions specific to the video? E.g in this case a question on Intermolecular Forces? :) Your vids are really helpful btw
Never mind! Watched the bit where you do some of the Past Paper questions!
***** Spot on!
Hey man thank you so much from the core of my heart.....
Very helpful, thank you so much. Can you please do a video for Sigma and Pi bonds for the CIE exam board?
+Tarek Adel I honestly haven't got the time at the minute. Sorry!