Column chromatography | Chemical processes | MCAT | Khan Academy

Learn how to separate chemicals using column chromatography. By Angela Guerrero. . Created by Angela Guerrero.
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[@Tennisplayer123]

im way too immature for the word stopcock lol

[@dinijay]

lol

[@bodybybarnes3795]

lol especially when she said "ramming it against the stopcock"

[@citronvertsoap]

LMAO

[@midosala8049]

Thank you, really helpful.

[@conjiii8372]

Thanks, that was really helpful.

[@kachingaaa]

Aw thank you so much, I'm a medical student but I'm in my 1st year and I'm excited to use this channel's videos for lab :D I also love her voice

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[@MaryGwozdz]

It would have been nice to know how the polarities of the molecules lead to them being separated as they ran through all of these different materials.

[@easylearning981]

+Mary Gwozdz In general, polar molecules elute more quickly than polar ones. This is because silica gel has polar character. On the other hand, if some apolar compound is adsorbed or covalently linked to silica gel, polar molecules will tend to elute first, as apolar ones will tend to interact intermolecularly with the surface of the covered silica.

[@emlmm88]

apolar molecules you mean.

[@iansteinke2414]

EASY LEARNING

[@iansteinke2414]

I think you have it a bit backwards

[@gaiusdaniel4221]

thank you

[@AmenIamHotepRA]

It would have been nice for you to mention what type of solvents are normally used, and the specific reasons for using each. Great video nonetheless.

[@paigec7596]

Go read some literature on it.

[@TruthAndLoyalty]

Great video.

[@lfcforever]

HAHAHAHAHAHA softcock 3:15

[@puppypi9668]

Oh holy cow, your voice is amazing! :'D And the video is really great content too! :DD I wish I could learn all the things from you :">

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@Karter Quentin yup, have been using Kaldrostream for since november myself :)

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@Karter Quentin yea, I've been using kaldroStream for years myself :)

[@smritisofia7691]

Alright.. but can someone tell me if purification of compounds by column chromatography depends on length of column or on state of solvent?

[@okoye.charles]

It depends on neither... Remember the seperation is mainly based on the seperation of immiscible and miscible liquids.

[@lilykeen6283]

this saved my ass. thank you

[@eludobudo]

Why the sudden change to a robot at 0:07? Haha

[@zarikhan1158]

Is Mobile phase or solvent contain that mixture that need to get separate??

[@abdullahshahnawaz6585]

No, the Mobile phase or the solvent is just itself... The Mixture ( as a whole itself) is added after the Solvent is poured into the Column...

[@Troncannone]

viva la delinquenza

[@dineshramgi9168]

It is good for child.

[@sccm100]

Orgo lab is a torture

[@MrBeachwaves]

The explanation from flask 1 to 2 is confusing. I don't get why different bands are showing up. The explanation of the set up was clear, but after that I got lost.

[@rathodmayur8714]

Can anybody please tell me , Why is ammonia vapor taken in spray of Rubinic acid in metal chromatography?

[@sparkunavailable]

to detect the presence of metal ions on the chromatogram. Rubinic acid, also known as ammonium molybdate, reacts with metal ions to form colored complexes that can be visualized on the paper or thin layer chromatography plate. For example, iron (III) ions form a blue complex, copper (II) ions form a green complex, and nickel (II) ions form a brown complex. Ammonia vapor helps to stabilize the complexes and enhance the color intensity.

[@johnstephenson2430]

Shouldnt the level of the solvent be dropping?

[@tylercantrell3379]

What is the purpose of adding the sand?

[@AmenIamHotepRA]

The sand is used primarily for the purpose of filtration.

[@KevDawg673]

The sand also acts as a bed support for the column bed, supporting whatever resin/gel is being used for purification. This is why she stresses making sure it winds up horizontal; a crooked bed support will cause a crooked column and give poor purification, which she demonstrated.

[@jrfw96]

Sound m9

[@sabahiqra8708]

Is Sunny leone speaking? :3

[@AmetafJohora]

no??

[@leehiufung911]

I am currently a PhD student in medicinal chemistry, and the very first thing that she says, is not really true. Chromatography is a terrible method to purify very large quantities of compound. Pharmaceutical companies need to be producing tens or hundreds of kilograms of compound, for a compound that is approved or in clinical development. Column chromatography is far too wasteful, in terms of the cost and environmental impact of the solvent and the silica gel. Crystallization is the preferred method, for drugs/compounds that have to be made in large quantities, in general. Now that isn't to say chromatography is useless. Usually, it is the method of choice when doing drug discovery initially, when far less of one particular compound is made (less than 10g, usually 50-100mg is enough), but many compounds need to be made and tested. Chromatography is also used as an analytical technique (HPLC-MS for instance), which can tell you how pure something is (kinda), for instance.

[@Chelssums]

i do not think this video was very helpful. There was no explanation of how and why they separate as well as the purpose of all of the "filters".

[@vlogvines1718]

Khan GS research center q😂😂

[@rojafx]

1:01 you sure you know how to spell clock right?

[@ibrahimfataw2352]

Stopcock not clock rojafx

[@erich3892]

rojafx this is why kids shouldnt be fucking teachers, sal needs to get off his rich ass and help us

[@ShenelleTaylor]

thank you

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Shenelle Taylor I luv u

[@Marcos-qn2ff]

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[@citronvertsoap]

no me more@@Marcos-qn2ff