María Ley Many thanks. I'm glad you found it useful. Distillation is so easily explained using laws taught in general chemistry, I will never understand why the text books don't teach it this way! Please share with your classmates and friends!
I am currently taking a chemical engineering mass transfer class, and this video helped me visualize a simple batch/differential distillation. Great explanation. Thanks!
What temperature is this theoretical distillation being done at? When you say your sample is 80% pure, over what range of temperature is that collected? And do you stop the temperature from increasing when it reaches the theoretical mixed-bp of the two liquids?
Hi! Where do I get the pressure of the liquids at the boiling point of the mixture? For example, I want to know those values for a 50% methanol water mixture
+sunshine If you are looking for a quick answer, you might be disappointed. You can, however, estimate those vapor pressures using Antoine's equation and the relevant constants for your components near the temperature in question. Here is a link to the Wiki page for the Antoine equation to get you started. en.wikipedia.org/wiki/Antoine_equation If you know or have measured the mixture's NBP, then you can use the Antoine Equation to get vapor pressure estimates and run a similar calculation to what I did in the video. There are various online resources that try to offer those constants, but to get the best numbers you will probably have to go to your university library for Yaw's handbook. app.knovel.com/web/toc.v/cid:kpYHACVPEH/viewerType:toc/root_slug:yaws-handbook-antoine/url_slug:yaws-handbook-antoine Of course, all of this hinges on ideal or pseudo-ideal behavior in your mixture, which is seldom the case. Methanol and water form one wicked azeotrope, so don't be disappointed if your calculations do not accurately reflect your results! Good luck! Professor D.
When you collect fractions, which liquid will be the one collected? Say for example I performed a simple distillation of methanol and propanol, how are they separated? Where do the separate liquids go?
I have a long winded question. Sense you have particles of different weights, would it make sense to have a greater than tube design>or the opposite with a valve at the first juncture to catch the heavier element and allowing the lighter element to carry on threw the second run and collected into a second basin? I hope that makes sense🤣
after having seen a few of these sort of videos I don't see how is that there are dumping lands where toxic waste is stored... where the important utopic argument is that there is no way to separate the toxic stuff back into its primordial elements... to me, it seems like these sort of videos prove that there are some good ways to deal with all sorts of pollutants/toxins and other junk that may have been created as a by product of a process
Hey fencer... the more volatile component will always elute first, since its vapor pressure is higher than the other. In your example, fractions collected early in the run would be enriched in methanol, while those collected later in the run would be enriched in propanol. Conventional wisdom says that a fractional still is needed to completely separate them from one another, since their BP's only differ by about 30 C.
thank you for the clear explanation sir ,but I think the calculation of the 80 percent of benzene is wrong , because you worked with 50 percent of benzene in liquid (which is just the value in the beginig and not also in the equilibrum where the pressures are equal and where you concluded the calculations) .
Hi Amine, Predicting the boiling point of a mixture ab-initio is pretty tough. You can try modelling them as ideal and using a set of parameters called Antoine's constants to determine at what temperature the boiling mixture will reach 760 torr pressure, but in the end it will be an estimate, because ideal behavior is so rare in this process. In short, you are best off determining the boiling points of mixtures empirically. Thanks for the comment!
So basically if you don't know the boiling point of the mixture the rest of the calculations are unreliable - since everything is based off of knowing the boiling point of the mixture. So unless you do lab experiments to determine the boiling point of the mixture the remainder of your calculations is a crap shoot? Not very reliable except as an exercise to show concepts - no real world application without lab testing to determine the actual boiling point of the mixture. I think you should emphasis how critical knowing the actual boiling point of the mixture is and how difficult it is to determine.
+sana jamshaid Hi Sana. I make these using a combination of MS PowerPoint, Perkin Elmer Chemdraw and Chem3D, Adobe Illustrator/Photoshop, Sony Movie Studio Platinum, Visual Molecular Dynamics (aka VMD) and even Autodesk Maya here and there when I have to pull out the big guns . The primary engine is PowerPoint, which I use to generate most of the motion that you see through animations. Occasionally I use Movie Studio to do some post-production editing and especially to add or edit audio. This video is one of my early attempts. I like to think that my production values are improving as I continue to manage the channel. Stay subscribed for many more videos this summer and fall! Also be sure to check out my Foundations of Organic Chemistry course with The Great Courses. For a limited time you can get a free one month trial to www.thegreatcoursesplus.com and watch my entire course and hundreds of others for FREE! Cheers, Professor D.
Although a Liebig might work here, a West is better choice. It is essentially a more slender version of the Liebig, which promotes greater contact between the vapor and the cold walls, increasing yield. Personally, I never understood why we bother to name them differently, but we do! Basically Liebigs are better for packing with loose solids as fractionating columns or for use in reflux apparatus, while West generally gives better recovery when used as the sidearm condenser of the still-head during distillation.
Separating fractions is simple. Just change collection flasks in the middle of a run. Do this as many times as you like. There is no rule about how many or how few you might want to collect!
*disclaimer*... please don't drink benzene or toluene. It tastes terrible, plus it will kill you.
You have no idea how much time you saved for me, thank you! You are still helping loads of people after 10 years!
this video really helped me A LOT.. i wish my teacher could make it this easy. thank you !
María Ley Many thanks. I'm glad you found it useful. Distillation is so easily explained using laws taught in general chemistry, I will never understand why the text books don't teach it this way! Please share with your classmates and friends!
Why benzene is more volatile than toluene? Why more vapour pressure P⁰ implies more volatility?
Please help
I am currently taking a chemical engineering mass transfer class, and this video helped me visualize a simple batch/differential distillation. Great explanation. Thanks!
Same here
What temperature is this theoretical distillation being done at? When you say your sample is 80% pure, over what range of temperature is that collected? And do you stop the temperature from increasing when it reaches the theoretical mixed-bp of the two liquids?
Hi! Where do I get the pressure of the liquids at the boiling point of the mixture? For example, I want to know those values for a 50% methanol water mixture
+sunshine If you are looking for a quick answer, you might be disappointed. You can, however, estimate those vapor pressures using Antoine's equation and the relevant constants for your components near the temperature in question. Here is a link to the Wiki page for the Antoine equation to get you started.
en.wikipedia.org/wiki/Antoine_equation
If you know or have measured the mixture's NBP, then you can use the Antoine Equation to get vapor pressure estimates and run a similar calculation to what I did in the video.
There are various online resources that try to offer those constants, but to get the best numbers you will probably have to go to your university library for Yaw's handbook.
app.knovel.com/web/toc.v/cid:kpYHACVPEH/viewerType:toc/root_slug:yaws-handbook-antoine/url_slug:yaws-handbook-antoine
Of course, all of this hinges on ideal or pseudo-ideal behavior in your mixture, which is seldom the case. Methanol and water form one wicked azeotrope, so don't be disappointed if your calculations do not accurately reflect your results! Good luck!
Professor D.
When you collect fractions, which liquid will be the one collected? Say for example I performed a simple distillation of methanol and propanol, how are they separated? Where do the separate liquids go?
I have a long winded question. Sense you have particles of different weights, would it make sense to have a greater than tube design>or the opposite with a valve at the first juncture to catch the heavier element and allowing the lighter element to carry on threw the second run and collected into a second basin? I hope that makes sense🤣
no
@@UniChannel-pg8ol is it because they are too close in atomic weight?
It's DNA intercalation-a-licious!
after having seen a few of these sort of videos I don't see how is that there are dumping lands where toxic waste is stored... where the important utopic argument is that there is no way to separate the toxic stuff back into its primordial elements... to me, it seems like these sort of videos prove that there are some good ways to deal with all sorts of pollutants/toxins and other junk that may have been created as a by product of a process
Hey fencer... the more volatile component will always elute first, since its vapor pressure is higher than the other. In your example, fractions collected early in the run would be enriched in methanol, while those collected later in the run would be enriched in propanol. Conventional wisdom says that a fractional still is needed to completely separate them from one another, since their BP's only differ by about 30 C.
to complicated this is an (intro) to simple distillation
Wow...just wow! this is awesome! Thanks...
Thank YOU! Please pass the video on by sharing, liking and subscribing :-)
thank you for the clear explanation sir ,but I think the calculation of the 80 percent of benzene is wrong , because you worked with 50 percent of benzene in liquid (which is just the value in the beginig and not also in the equilibrum where the pressures are equal and where you concluded the calculations) .
Perfect explanation method
I am Ph.D students but in my life this type very perfect explanation chemistry first time watch
Hi Amine,
Predicting the boiling point of a mixture ab-initio is pretty tough. You can try modelling them as ideal and using a set of parameters called Antoine's constants to determine at what temperature the boiling mixture will reach 760 torr pressure, but in the end it will be an estimate, because ideal behavior is so rare in this process. In short, you are best off determining the boiling points of mixtures empirically. Thanks for the comment!
So basically if you don't know the boiling point of the mixture the rest of the calculations are unreliable - since everything is based off of knowing the boiling point of the mixture. So unless you do lab experiments to determine the boiling point of the mixture the remainder of your calculations is a crap shoot? Not very reliable except as an exercise to show concepts - no real world application without lab testing to determine the actual boiling point of the mixture. I think you should emphasis how critical knowing the actual boiling point of the mixture is and how difficult it is to determine.
really great video thank you sir
how does this channel only have 54k subs???
Wait but what about azeatropes and how the composition is constantly changing?
Not so simple though! Lol
Chemsurvival.. What animation software do you use!?
its really awesome.........could you also explain the mass balance calculation for distillation???
Thanks a lot Doctor ... Just i want to know how to define the boiling point of mixture
could anyone please tell me how these video tutorials can be made? I mean which software is used to make these video tutorials?
+sana jamshaid Hi Sana. I make these using a combination of MS PowerPoint, Perkin Elmer Chemdraw and Chem3D, Adobe Illustrator/Photoshop, Sony Movie Studio Platinum, Visual Molecular Dynamics (aka VMD) and even Autodesk Maya here and there when I have to pull out the big guns . The primary engine is PowerPoint, which I use to generate most of the motion that you see through animations. Occasionally I use Movie Studio to do some post-production editing and especially to add or edit audio. This video is one of my early attempts. I like to think that my production values are improving as I continue to manage the channel. Stay subscribed for many more videos this summer and fall!
Also be sure to check out my Foundations of Organic Chemistry course with The Great Courses. For a limited time you can get a free one month trial to www.thegreatcoursesplus.com and watch my entire course and hundreds of others for FREE!
Cheers,
Professor D.
Maybe someone called West also made this kind of condenser. The correct term however will be Liebig condenser.
Although a Liebig might work here, a West is better choice. It is essentially a more slender version of the Liebig, which promotes greater contact between the vapor and the cold walls, increasing yield. Personally, I never understood why we bother to name them differently, but we do!
Basically Liebigs are better for packing with loose solids as fractionating columns or for use in reflux apparatus, while West generally gives better recovery when used as the sidearm condenser of the still-head during distillation.
ChemSurvival Ok..i see. Thanks for explaining it so detailed.
Thanks it helped me for my seminar
i'm so glad it helped :-) Good luck with your seminar!
Separating fractions is simple. Just change collection flasks in the middle of a run. Do this as many times as you like. There is no rule about how many or how few you might want to collect!
Children
Tracheal
DCCC
Excellent demonstration
Thank you!
Thanks a lot!
this guy knows how to make interesting things boring via the way he talks