Thin layer chromatography (TLC) | Chemical processes | MCAT | Khan Academy

[@novacrystalas]

You explained TLC better than my university chemistry professor in half the time.

[@panagiotisatmatzidis9972]

I wonder if that's because in the class we don't pay any attention, while in the exam session our dopamin/serotonin receptors suddenly get busy... Or some people are just charismatic while others, simply are not.

[@novacrystalas]

Panagiotis Atmatzidis No, I really do believe her explanation was simply great. My chemistry class had severely curved grading because everyone basically failed. I suspect that everyone did poorly because the professor was not good at lecturing. The professor was a wonderful and likeable person, but his lectures were bad. For example I got something like 50% on the final and received an A- in the course because the grading was adjusted so much. Everyone in that class had horrible grades. My test marks were usually 30-40% higher than the class average, but I still felt like nothing made sense in his class... I really did try hard and pay attention too.

[@mohdmursal4104]

I agree

[@ernakristiana365]

@@panagiotisatmatzidis9972 haha true😆

[@Yehuditwolfe]

@@novacrystalas is this professor from LA lol?

[@saff1257]

stationary phase: the plate with silica gel on it mobile phase: the solvent or mixture of solvents in a beaker draw a pencil line 10mm up on the plate. use a toothpick to dot the sample onto the plate put 9mm2 of the solvent in a beaker. place plate in beaker. add a lid. wait for the mobile phase to move, until it’s almost at the top. take it out and draw a pencil line where it got up to. use a uv lamp to see the results. parts that moved further were more attracted to the solvent- less polar. parts that moved less far were more attracted to the silica (which is very polar) - so they are more polar

[@saff1257]

moved far: less polar attracted more to solvent moved not far: more polar attracted more to silica gel silica gel is very polar

[@Yehuditwolfe]

I think this is wrong explaination! moved far: less polar, less attracted to the solvent moved not far: more polar, more attracted to the solvent solvent is polar.

[@jobis34]

yehudit wolfe No silica gel is polar. She even said that in the video. So they will use a non-polar mobile phase. They CAN switch those two.. but in this video that was the case

[@antonymp1992]

@@jobis34 👍

[@deltaloraine]

THANK YOU! I have my organic chemistry lab this afternoon and the lab manual did not explain clearly what the TLC experiment was going to look like. I feel more confident now haha

[@c.leonoranymo2232]

oh boy, did you just save my ass

[@angeecelinova7760]

The way my profesor explained was in such way I didn't understand at all. Your graphic really helped me, thank you

[@gullofficial]

You saved my time and made this concept crystal clear to me.. Thank you very much ☺☺✨

[@MrLolza69]

Thanks for the help! Good for high school as well :P

[@rabiya5229]

Clear and concise explanation. Thank you!

[@laarayb97]

Im doing this in yr 12 chemistry and I was so confused, but this vedio absoloutly cleared TLC for me, perfect :D

[@noshintarannum9152]

Thank you so much! i have all my confusions cleared out!

[@kisaflwr]

Oh god, I have an o chem test tomorrow, and this helped me so much..thankyou!

[@comoplaysdestiny5106]

how did the test go?

[@akhil1802]

@@comoplaysdestiny5106 lmao 2 years ago. I'm pretty sure she/he would've forgotten

[@rajaroychoudhuri7451]

Thanks khan academy for such alucid exploration

[@relaxingsounds91553]

You are a life saver ❤

[@lawson9738]

Your Welcome 😁

[@ChemicalEngineeringGuy]

beautiful and effective explanation =)

[@ilhanthediamondcrafter9767]

Thank you for the knowledge

[@A_copywriter]

Thank you very much💕

[@adityaiyengar152]

Awesome explanation! Thanks!

[@MrMusicLyrics12]

Thank you! I am doing this for school :P ty :D

[@quinxx12]

Your voice to me is what the silica gel is to the polar compound :DD

[@AdityaSharma-tc5fp]

we can even use ninhydrine for visualization of spots

[@Spoooky738]

Aditya Sharma only for aminoacids

[@jddasadia]

thnks i got my all fundas clear...........

[@Keyvan100]

fire.

[@salehalhalabi4127]

Thank you so much you helped me a lot ❤

[@Angelub]

THANK YOU! I hate reading my MCAT books, this helps

[@moseshayab8497]

This piece was really simple and understandable. Thanks a lot. more insight to you, dear.

[@dishnihareen3703]

thank you. this helped me a lot to get through my lessons. nice work, well done

[@bhaveshverma1906]

very good video for study tlc chromatography

[@WorldRandom3D]

Perfect for F324

[@yoony8856]

thank u sooooo much !!!

[@philipmcniel4908]

I realized in lab this morning that if you used letter-writing paper for TLC, you would literally have a "stationery phase"

[@sehajpreetkaur4604]

Amazing video❤

[@shankysingam]

Brilliant explanation. Very useful

[@leeman4394]

Hell ya baby i love TLC, especially the my 600lbs wife videos and sister wives

[@thalesm4056]

I loved this explanation. thanks

[@kakeungchu2173]

an cutie tone

[@SteveAustin00]

Wow

[@reubenfernandes9917]

*An cute tone

[@afroditi5760]

@@reubenfernandes9917 a*

[@BuffaloZx]

Usually like this channel but I don't think a simple topic could be explained with any more complexity than in this tutorial

[@abramgrey2237]

You saved me!!❤

[@josh.c36]

Could you do one on paper chromatography with a polar solvent?

[@sanjaycsalunkhe5381]

with this i can get passed for 3rd level homi bhaba 6th grade

[@rasha341]

thank you 😃

[@anikaterajiv7381]

What an amazing voice

[@foolstudent8669]

nice video! thank you :)

[@ahmedramzy8327]

this was just perfect 😍

[@rembeck8549]

Thank you!

[@oydeekoi8271]

Thank you so much! :)

[@nuni2136]

thanks.

[@cek3800]

Well explained!!!!

[@INCGJEntertainment]

thanks !!

[@Eren-gc9ne]

You are amazing

[@ellien4191]

Thank you! And can I ask what programme you use to record your voice and what you're doing? Thanks!!

[@lixx1414]

GRACIAS

[@titi14fan]

thank u

[@alinahussain92]

Helpful...

[@nadamouradelzayat7833]

Please, I want the method of separation mixture of soluble acid and soluble phenols

[@idarmistorres3156]

great!!

[@mariammansour291]

What if you use a polar solvent? Would that change the distance the spots travel? Wouldn't the nonpolar compound not travel as much because of the polar solvent?

[@jordanjuan9]

it would be opposite effect

[@kennyyong7694]

Excuse me, do you know how to prepare silica gel to absorb moisture or silica gel to act as the stationary phase in thin layer chromatography. I need to prepare TLC plate by my own.

[@nabilaaulia9361]

And now I know, finally.............. :")

[@Leen-ih8ql]

what are the methods or ways of separating plant pigments?? only TLC and paper chromatography ?? please I need help

[@bettinahurlimann3420]

Thank u so much!! U literally saved my ass!

[@doda-os3bp]

why is it called separation method isnt it just straight up detection

[@mercedesmalone973]

what is the Rf ????

[@andreistephen4965]

the Rf vale is the distance moved by the component or part of the original substance/ the solvent front the point the solvent moved up to. =)

[@mercedesmalone973]

so sad that most chemistry books dont cover this. how does rf value relate to polarity?

[@andreistephen4965]

Mercedes Malone I have not gotten to that yet on my course but I belive it has something to do with weather the component is more attracted to the plate or the solvent if it is more attractedbto the plate It only moves a littel uf it is attraxted to the solvent it moves alot I dont really know feel free to correct me

[@hyeballer]

+Mercedes Malone Rf value's can help determine which spot is more polar (lower the spot = more polar)... However, TLC spots may vary due to the size and shape of the molecule. So to simply say that a spot is "more polar" because its lower isn't necessarily 100% correct.

[@misssweethearted]

hyeballer actually Rf values tell you about the affinity of the solute to the TLC plate. A high Rf value means a lower affinity for the TLC plate and greater solubility in the solvent.

[@shaweeeeng5963]

What's little spot there in stationary phase?

[@aadityatiwari5676]

isnt silica overall nonpolar tho...if its the stationary phase why did she call it very polar?

[@VirgiliusRomanus]

are you mentioning what happens when the solvent is polar or nonpolar??? You should. Otherwise this is an incomplete explanation.

[@LilyLi33]

Isn't the stationary phase always polar and the mobile phase always nonpolar?

[@LilyLi33]

AnetheronOriginal Yeah, I've learned a lot at my internship. Solvents, duh! Sorry, I'm only in my first year of high school so :P

[@easylearning981]

+Lily Li In this type of chromatography, compounds with more affinity to the solvent will travel further along with the solvent.

[@PrideofPitchers]

+VirgiliusRomanus She explained the polarity of the solvent briefly, but not a solvent that consists of compounds with different polarities. For example, you could have a mixture of 5 parts ethyl acetate and 95 parts hexane (hexane being nonpolar) as your solvent, which will affect the distribution of compounds on the plate. In this case, nonpolar compounds won't be attracted to the stationary silicone phase or acetate and will travel very high up the plate because of their affinity to hexane. Polar compounds won't likely move very far because 5 parts acetate isn't polar enough to break that adsorption to the silicone plating. hope that helped.

[@BrokenTwistedPrince]

PrideofPitchers you make some interesting points, do you know anything about the affinity of aluminium backed microcrystalline cellulose thin layer plates during the stationary and mobile phase?

[@eisenj21188]

why do u have to remove your plate just a little before it reaches the top and not just let it go all the way?

[@maryc5905]

the components that you were trying to separate will end up all reaching the end and run off the TLC plate along with the solvent

[@hyeballer]

Josh... Technically speaking, you can let it go to the top...as long as you remove it the moment it reaches the top. As Mary C stated, if you were to leave it a prolonged period the spots will continue to run up.

[@Un1ted-Kingdom]

Good :)

[@tgrmln93]

God, ur lovely voice.... make me wanna.... thanks for ur great explanations :)

[@brutalpsychedic]

2020 and they are still hot

[@theresiafeline2485]

I think silica is non-polar???

[@ac4190]

Silica, (SiO2)x, is polar due to the polarity exhibited between the oxygen and silicon atoms. The silicon atoms are more electropositive than oxygen, and oxygen atoms are more electronegative than silicon.

[@BigChungusthe3rd]

Why does she say nonpolar molecules are attracted to the mobile phase, when the mobile phase is at the bottom? Why does it travel up higher? If someone knows and could answer it'd be much appreciated!

[@meinkanta]

The mobile phase has travelled up the TLC plate by capillary action - the purple line she drew on the top of the TLC plate inticates how far the mobile phase moved. The less polar molecule being more attracted to the mobile phase means it moved further.

[@meinkanta]

+Arsank47 That sounds more like Gas Chromatography?

[@meinkanta]

+Arsank47 Okay, so your stationary phase would be the TLC plate, which probably uses silica. The mobile phase is the solvent you're using. I'm not sure about the others, but I'd guess the detection system would be calculation of the Rf values and comparing them to a database.

[@deephealthcare]

hindi me bhi kuj lessons banaye aap

[@Not_LaGGy999]

damn this was a mess in my head before I find this video

[@imosdefinite]

what's a spotter?

[@imosdefinite]

0:50

[@lina4469]

you know, it'd be real cool iof you didn't write in cursive

[@shannondove96]

can chromatography work with extremely small concentration, ....for example if you're trying to separate something out that is in the parts per trillion range?

[@rafaelm3657]

MY FUCKING G. LOVE YOU

[@foofpilled]

chromatography is pain

[@cridtianromero7022]

2ryri

[@boosandblues3118]

ur voice is um idk how to explain

[@sagarmdod8896]

Thanks a bunch!, very informative (and of course, very sexy voice! ;-) )

[@mirlandewilson8267]

A very simple explanation and to the point. Thank you!

[@bapkim-ib9uj]

thank you !

[@directionerforever1238]

THANKS SM

[@totalfootball4452]

very well explained . Thanks

[@fejiroedeki]

Thank youuu

[@EndermanBoss]

Thanks

[@lauren9004]

Thank you!

[@MaideCanyakar]

Thank you

[@SaadSaad-mb4py]

Thank you

[@whysocareless2926]

Thank you

[@alhaeri1]

thank you