Hello all, @2.20 ,I am talking about Resonance energy per benzene ring. Here is the detailed write up 👇👇👇👇👇👇👇👇 The resonance energy for phenanthrene is 92 Kcal/mol, anthracene is 84 Kcal/mol ,(3 Rings) naphthalene is 61 Kcal/mol(2 rings) benzene is 36 Kcal/mol.(1 Ring) *Note* : For polycyclic aromatic hydrocarbons, stability can be said to be proportional to *resonance energy per benzene rings.* Here resonance energy *per benzene ring* decreases from 36 Kcal/mol for benzene to 30.5 Kcal/mol for naphthalene, 30.3 Kcal/mol for phenanthene and 28 Kcal/mol for anthracene. Hence, order of stability (or RE): Benzene > Phenanthrene ~ Naphthalene > Anthracene. In fact other fused polycyclic aromatic hydrocarbons react faster than benzene. *Benzene vs Naphthalene* Benzene has *six pi electrons* for its single aromatic ring. Naphthalene has two aromatic rings, but *only 10 pi electrons* (rather than the twelve electrons that it would prefer). This means that naphthalene has less aromatic stability than two isolated benzene rings would have. The same argument applies as you keep increasing the number of aromatic rings -the number of pi electrons does not increase in proportion to the number of aromatic rings, which results in decreased stability. Additionally, when you react these fused aromatic rings, they always react to generate the most benzene rings possible. For example - anthracene will react at its center ring, which generates two isolated benzene rings in the product, rather than at the terminal ring (which generates a naphthalene ring system in the product).
it's a good video but (sorry for saying it like this) you have quite a strong accent so I missed some things... Could you put some subtitles ? I think it would help a lot of people. Thanks :)
Hello all, @2.20 ,I am talking about Resonance energy per benzene ring.
Here is the detailed write up
👇👇👇👇👇👇👇👇
The resonance energy for phenanthrene is 92 Kcal/mol,
anthracene is 84 Kcal/mol ,(3 Rings)
naphthalene is 61 Kcal/mol(2 rings)
benzene is 36 Kcal/mol.(1 Ring)
*Note* : For polycyclic aromatic hydrocarbons, stability can be said to be proportional to *resonance energy per benzene rings.*
Here resonance energy *per benzene ring* decreases from 36 Kcal/mol for benzene to
30.5 Kcal/mol for naphthalene,
30.3 Kcal/mol for phenanthene and
28 Kcal/mol for anthracene.
Hence, order of stability (or RE): Benzene > Phenanthrene ~ Naphthalene > Anthracene. In fact other fused polycyclic aromatic hydrocarbons react faster than benzene.
*Benzene vs Naphthalene*
Benzene has *six pi electrons* for its single aromatic ring. Naphthalene has two aromatic rings, but *only 10 pi electrons* (rather than the twelve electrons that it would prefer). This means that naphthalene has less aromatic stability than two isolated benzene rings would have. The same argument applies as you keep increasing the number of aromatic rings -the number of pi electrons does not increase in proportion to the number of aromatic rings, which results in decreased stability. Additionally, when you react these fused aromatic rings, they always react to generate the most benzene rings possible. For example - anthracene will react at its center ring, which generates two isolated benzene rings in the product, rather than at the terminal ring (which generates a naphthalene ring system in the product).
Super sir one of the best teacher ur I'm impressed 👌👌👌👌👌👌👍👍👍👍👍👍👍
Maaazaaa.... Mazaa... Maza.... 🙏🙏🙏🙏💃tqq sir ji
Dear Nikhil it was a pleasant surprise....will be glad to use the video to teach the topic to your super juniors. Keep up
Omg, this comment made my day,😃 tysm sir, just passing on the knowledge and wisdom I received from great teachers like you😊
Resonance of double and triple ring structures ka bta Dy.
Thank you
It's helpful video 😁 thnku ❤️
One shot goc with tricks can be very helpful 👍💯
Ok Bhushan.. Shall research on previous year qns and make the video of most expected qns!
@@TUCTheUnforgottenChemistry ok sir👍
Sir, hydrogen konse position se niklega 9 ya 10.
Sir.... Just awesome!!!! Pls do make a video on resonance energy toooo!!! These small concept videos are just amazing!!!! Thank youuu so much!!!
Carry on sir, i hear u like awesome , plz make on pharmacy lecture
please explain disubstituted
Mind blowing sir
why sulphonation of anthracene occurs mainly at position 2 and not at position 9 why ..
Sir give answer as soon as posible
Sir EAS of phenanthrene also ..
Nice video sir. 👏👏
But one doubt. What is the number of resonating structures anthracene will form when electrophile attack on ninth position?
Thank you sir :)
Resonance energy of anthracene is more than resonance energy of naphthalene and benzene
Hi, Ty for noticing, I am talking about RE per benzene ring, I have put up that in comment section. Plz go through. Tysm😊
it's a good video but (sorry for saying it like this) you have quite a strong accent so I missed some things... Could you put some subtitles ? I think it would help a lot of people. Thanks :)
👍🏻👍🏻👍🏻❤
Kyu hai aisa numbring reason