Thanks a lot. You don't understand how much you are helping people from around the world. I can't thank Khan Academy enough for doing what they do. Keep it up!
I personally think that Khan Academy is the best source of online learning. When I first encountered this youtube channel i thought for a second. wait "Would I be able to understand,possibility are there might be few terms which might be used in the video which might not be explained or talked about in my reference book" But trust me, it covers every single term and concept. I sometime wander whether he had read my course book or what lol
Ok. I barely studied this entire semester, got 71, 42 and 50 on my 3 tests and 90 on my final. Thank you so much, I literally learned organic chem I in one night, and aced my final. I honestly just dont get it why cant the teachers be like you, you're so clear and your explanations are wonderful! Thanks again Sal :)
During a UV free radical chlorination you say to use UV light. So just for fun I used the formula E=hf and figured out the charge in joules of a 400 nm UV light (6.626 X 10*-19 J) which is the WEAKEST UV wavelength and I found out it is more than enough joules for homolytic bond cleavage not only in the chlorine BUT ALSO in a Cl/C bond. I found the dissociation bond energies from charts on line. So let us say I have DCM and want to make tetrachloromethane. So if I use the weakest UV...…..400 nm then I have enough energy in the UV to not only break Cl/Cl bonds but also the Cl/C bonds that I want to make. THAT DOES NOT MAKE SENSE ?????????????????? Let us say I want to make benzyl chloride. 400 nm UV light is SLIGHTLY more joules needed to break a benzyl C/H bond (6.26 X 10*-19 J) and WAY MORE THAN ENOUGH to break a benzyl C/Cl bond. Do you see my point. As I make the product the UV light is enough energy to destroy what I make. So how does it work??????????????????? Also the UV light at 400 nm is enough to turn the whole pot of toluene into benzyl radicals that combine with each other as much as the chlorine.....it seems like that would not be good??????????????????????????? Also I looked up the energy needed to break a Cl/Cl bond (4 X 10*-19 J) and that corresponds to a light source of ABOUT 500 nm...……..WHICH IS GREEN VISABLE LIGHT. Although at this point I was really frustrated and started doing math in my head but it is close. So now I am really confused because that means you do not even need UV light to make Cl free radicals. SO is this true?????????? Can I make Cl free radicals with green visible light?????????? IF SO THEN WOULD IT NOT BE BETTER to use 450 nm blue visible light with NO UV light. That way the photons are slightly under the energy needed to break benzyl Cl/C bonds and benzyl C/H bonds and in the case of an ALKYL chloride blue light is not enough to break Cl/C bonds. BUT blue light is good enough to break Cl/Cl bonds so your product wont be destroyed as you make it by UV light. I thought I had a good understanding of free radical halogenation until I did the math. WHAT IS THE DEAL. HELP ME HELP ME HELP ME PLEASE
when you realise even at alevel uk they dont go over basic uni notation... ie sn11/2 e1/2 i mean we are taugh it but not explicitly told what sn2 is etc or the differences
Hey Khan, it would be cool if you could put up some videos about retrosynthesis(working backwards) and Lindlar's, NaH, NaNH2, Pd/C and all that jazz. That'd help me out a lot in my ochem class
the overall reaction is CH4 + Cl2 > CH3Cl + HCl so if once through homolysis chlorine free radicals are formed after breaking the only Cl molecule..then where did another Chlorine molecule come from?
#YouCanLearnAnything except how Antioxidants work on a mechanical level, you just have to trust that they do what we're told "correct the free radical".
Hey there! I wanted to stay thanks for helping me throughout my MCAT studying! However, I thought when Methane reacts with the first chlorine radical and becomes methyl chloride, a second Chlorine is NOT able to react with the methyl chloride create because the C-H bond is no longer weak? In fact, the weakest bond becomes the C-Cl bond because the carbon becomes somewhat positive, so the C-H bond is not that polar, and thus, strong. So it would just replace the current C-Cl bond for another
So how much energy does it need, exactly, to break this Cl-Cl bond? What amount of heat? Or what intensity and wavelength of the UV light? And how do we know that?
if we could have complete preperation of csir net chemistry on khan academy with question solving and theory ,it would be very very helpfull and very beneficial for us.
+Heisenberg Edison dude, do u kno about the conditions of Pakistan which is an Islamic Republic? if we are Muslims, why would we be killing our own kin? These things hav to be thought about with a chilled mind.
i love how he says everything twice, like he knows i am easily distracted XD
i wonder what this guy is up to nowadays.
@@OER888 he's into... oh wait, he got distracted
I love how casually you guys are chatting like frd😏😂😆
@MrUnladenswallow definitely 😂
How are u all.... Still alive ?
Thanks a lot. You don't understand how much you are helping people from around the world. I can't thank Khan Academy enough for doing what they do. Keep it up!
make donations if you really wanna help them
Behnam Ghane is this your voice in above videos
@@rezapahlaviisking .
Baba Khan no
I only liked ur comment bcuz u like GnR
I personally think that Khan Academy is the best source of online learning. When I first encountered this youtube channel i thought for a second. wait "Would I be able to understand,possibility are there might be few terms which might be used in the video which might not be explained or talked about in my reference book" But trust me, it covers every single term and concept. I sometime wander whether he had read my course book or what lol
I also had the same problem to. Thank God n thank Khan Academy for making it easy for us.
Ok. I barely studied this entire semester, got 71, 42 and 50 on my 3 tests and 90 on my final. Thank you so much, I literally learned organic chem I in one night, and aced my final. I honestly just dont get it why cant the teachers be like you, you're so clear and your explanations are wonderful! Thanks again Sal :)
How's life now? It's been 10 years 😄
@@kyonhihorahipadhaifr r u a scientist now a doctor what happened 😂
@@hegresal-jubury8839 Yeah, we're curious 😸
No reply unsuccessful 😂
btw... 4 mins 55 secs (approx) in he says ''the carbon does the same'', i think he means chlorine
explained better than my professor!
why cant you teach at my uni!! you are the best seriously Ive been watching your videos since high school .
Imagine making a video that is watchable even after 13 years
At first I was put off by the rough diagrams but you helped me understand this a lil more. Will surely be returning throughout my A-levels! :)
1:42 "if it was upto me"................well dont worry sal its completely upto you....the future of chemistry is in ur hands :P
Respected sir ,
I am just mesmerised with your teaching .I am from India sir lots of love to you sir
You made me love chemistry. Thank you so much.
Not all Heroes wear caps
Leen Minr capes
moops
Idk any heroes that wear caps tbh
So True
some wear capes
Explanation that even a dumb like me can understand! Thank you so much, and nice job!
but a dumb like me don't even understand :´´(
@@03raq lol
Had to watch it twice..got distracted by my face staring back at me.🙃
🤣🤣
this is one of the best educational channels out there .
Love how you repeat words :P Thanks man
Thank you so much! You're a life saver. When I become rich I'll make sure to donate lots to Khan Academy. You guys are absolute legends!
i hope youre a millionaire by now
@@bonk_rl i failed my A levels LOL
Dw just ask me again in 5 years and I’ll say yes
@@STICKY_ that's the spirit!
@@STICKY_ i hope ur a billionare by now 😅...
I love how he repeats stuff! :)
Love you Sal beautiful voice but most importantly you have the ability to teach concepts better than any other
Thank you so much for posting this! Now, I've finally understand what free radical reaction really is about..! =)) Keep up the good work! ^^
Thank you so much Mr Khan! After weeks of trying to understand this process it finally makes sense after watching your video. Thank you.
I got an A on my quiz because of this video!!
Thank you so much for this video!!! 😭😭❤️❤️❤️❤️❤️💕💕💕💕💕💕
You've helped me a lot!!!!! Love yaaa! ❤️💕💕💕💕💕
During a UV free radical chlorination you say to use UV light. So just for fun I used the formula E=hf and figured out the charge in joules of a 400 nm UV light (6.626 X 10*-19 J) which is the WEAKEST UV wavelength and I found out it is more than enough joules for homolytic bond cleavage not only in the chlorine BUT ALSO in a Cl/C bond. I found the dissociation bond energies from charts on line. So let us say I have DCM and want to make tetrachloromethane. So if I use the weakest UV...…..400 nm then I have enough energy in the UV to not only break Cl/Cl bonds but also the Cl/C bonds that I want to make. THAT DOES NOT MAKE SENSE ?????????????????? Let us say I want to make benzyl chloride. 400 nm UV light is SLIGHTLY more joules needed to break a benzyl C/H bond (6.26 X 10*-19 J) and WAY MORE THAN ENOUGH to break a benzyl C/Cl bond. Do you see my point. As I make the product the UV light is enough energy to destroy what I make. So how does it work??????????????????? Also the UV light at 400 nm is enough to turn the whole pot of toluene into benzyl radicals that combine with each other as much as the chlorine.....it seems like that would not be good??????????????????????????? Also I looked up the energy needed to break a Cl/Cl bond (4 X 10*-19 J) and that corresponds to a light source of ABOUT 500 nm...……..WHICH IS GREEN VISABLE LIGHT. Although at this point I was really frustrated and started doing math in my head but it is close. So now I am really confused because that means you do not even need UV light to make Cl free radicals. SO is this true?????????? Can I make Cl free radicals with green visible light?????????? IF SO THEN WOULD IT NOT BE BETTER to use 450 nm blue visible light with NO UV light. That way the photons are slightly under the energy needed to break benzyl Cl/C bonds and benzyl C/H bonds and in the case of an ALKYL chloride blue light is not enough to break Cl/C bonds. BUT blue light is good enough to break Cl/Cl bonds so your product wont be destroyed as you make it by UV light. I thought I had a good understanding of free radical halogenation until I did the math. WHAT IS THE DEAL. HELP ME HELP ME HELP ME PLEASE
I had lost my mind after reading this sir🤣😂
i have no words to thanks the great khan academy....
I love this guy. Seriously 😂😂. He can explain in simpler way than my chemistry lecturer.
when you realise even at alevel uk they dont go over basic uni notation... ie sn11/2 e1/2
i mean we are taugh it but not explicitly told what sn2 is etc or the differences
many thanks khan, using your videos for a lot of my upper division classes now
thank you so much, it makes so much more sense
You just have to love the voice of sal😅
Man you're a genius teacher.
Thank you for the clear presentation. very helpful
thanks khan academy.............u helped me for my chem exam
Hey Khan, it would be cool if you could put up some videos about retrosynthesis(working backwards) and Lindlar's, NaH, NaNH2, Pd/C and all that jazz. That'd help me out a lot in my ochem class
Explained better than my Ph.D
THANKS A BILLION!!!
Thanks for the help! Science Fair in a couple of days... So pumped!
Thanks a lot it has really helped me
best teacher ever!
the overall reaction is CH4 + Cl2 > CH3Cl + HCl
so if once through homolysis chlorine free radicals are formed after breaking the only Cl molecule..then where did another Chlorine molecule come from?
Nice explanation sir!!!
I wish you were my lecturer
These videos help me out soo much! Thanks @khanacademy and this man's voice! :D
720p looks amazing!
Thank you. You saved my life.
I think that's cause youre smart - with all due respect and acknowledgement to Sal.
It saved my Chemistry exam!!!!!
#YouCanLearnAnything except how Antioxidants work on a mechanical level, you just have to trust that they do what we're told "correct the free radical".
bless Sal Khan's soul
You help me a lot! I am ever so grateful : ) Keep it up, you're great!
You the man Khan. Never change #ATownBeBallin
the way of teaching is very good 👍
Hey there! I wanted to stay thanks for helping me throughout my MCAT studying! However, I thought when Methane reacts with the first chlorine radical and becomes methyl chloride, a second Chlorine is NOT able to react with the methyl chloride create because the C-H bond is no longer weak? In fact, the weakest bond becomes the C-Cl bond because the carbon becomes somewhat positive, so the C-H bond is not that polar, and thus, strong. So it would just replace the current C-Cl bond for another
nice job! thanks! Curious why you repeat the same word so many times, but besides that it was perfect.
thank you so much...i'm am goin to ace my first year finals...oh yeah....:D
its been 8 yrs how did u do?
@@ZAsym I don't need sleep, I need answers.
@@kamaya9907 mine went well, I’m happy with my grade :D
Instructor non-verbal cues purssued im a punk. Glad this video! Diction is good for academic colab commnication.
THANK YOU SO SO MUCH! I WOULD FAIL SCHOOL WITHOUT KHAN ACADEMY
cheers khan academy, first time watching one of your videos and I am very impressed
Brilliant video, well explained, Thankyou! But it is very distracting when you repeat yourself
Thanks Khan.
lol I am so subscribing!!! you are really good explaining! I get extremely lost in my chemistry class. Thank you so much!!
Love khan academy...amazing !!!!
superb.. thankss a lot i really gotr a lot of help
thanks sir .. u really gave me a proper understanding about the steps and radicals
Great stuff man! The repeating is fine and actually helps.
Keep doing what you do!
thank-you, lots of love
Thank You so much!!
Like, i really love your videos and just the whole institution. Thank you.
Watching from Bangladesh
Thank you
Thank you very much
thanks!!
Thank you sal!
Godly explanation cheers!
your explanations are great!
Thanks a lot!
thank you khan sir
Beautifully explained sir !!!
Thank u
very useful thank u !! 😫😫❤️❤️
God bless you😭💜💜
So how much energy does it need, exactly, to break this Cl-Cl bond? What amount of heat? Or what intensity and wavelength of the UV light? And how do we know that?
you saved me
ektu pore presemtatiom ase
Gracias.
thank for this vedio..
THANK YOU MY BROTHER
excellent explanation !! Thanks a lot !!
if we could have complete preperation of csir net chemistry on khan academy with question solving and theory ,it would be very very helpfull and very beneficial for us.
You are the best😢😢😢😢😢😢😢
THANKS AGAIN......
I was 4 years old when this video came out
Great video!
THANK YOUUUUUU I LOVE YOU MAN !!!!! YOU SAVED MY LIFE
What :(
lol okay
excuse me?!
Thanks so much I have never thought I would understand this reaction😊❤
thank you sooooooooooo much!
Thank you very much Khan Academy, you have really been a great help to me, very clear and easy to understand. Keep up the good work. :-)
+Heisenberg Edison what's your problem. u have issues big one at that
shut up
yes, u, world @#$%$!
any prob? then keep it to ur butt
+Heisenberg Edison
dude, do u kno about the conditions of Pakistan which is an Islamic Republic? if we are Muslims, why would we be killing our own kin? These things hav to be thought about with a chilled mind.
i like this video!
may god bless u brother, like fr
thanks!
Good. Keep on going.