Since our schools have moved to online schooling and we are doing our organic 2 labs "online", your video helped me understand this much better than my professor's handout!!! Thanks!
Really helpful! Since classes turned online...my teacher has been using these videos to give us an accurate image of it. I think I should give you some love in Patreon!
Thank you for this Since our college is now oprate online lecture I was unable to understand this during my journal completion but now after watching this I can do it easily Thank you 💖
Thank you for posting this, as mentioned previously my college has also moved all classes including labs online. Your video helped me understand the procedure better and thank you for going over the mechanism :)
can you explain why you use that much amount of benzaldehyde and aceton? I need to use 0,05 mole of benz with the quantity of acetone but i cant figure out. :(
What is the red color when we first add the half of benzaldehyde and acetone in NaOH solvent?. Two days ago, when doing this experiments, i surprised about this. So I wonder what is the red color?
GREAT VIDEO.......GREAT CRYSTALS..........I want to do an aldol condensation between acetone and acetone to make 2_methyl_4_oxo_2_pentanene. And then destroy the double bond with KMnO4 and make pyruvic acid and acetone.
One of the electron pairs of the double bond of the enolate attacks the carbon of the aldehyde group. An electron pair of the negatively charged oxygen in the enolate moves down, which leads to a ketone in the former enolate.
I guess it's due to the possibility that a Cannizzaro reaction might be possible. (Aldehyde in alkaline conditions) And the aldol condensation between acetone molecules is also an option. (Formation of diacetone alcohol)
@@RaExpIn I know I’m quite late, but if the Cannizzaro has a possibility to occur, why does colder temperatures prevent it? Shouldn’t it still continue?
I already had someone asking this, so here you go :) Molar Masses: Benzaldehyde 106.121 g/mol Acetone 58.08 g/mol Dibenzalacetone 234.29 g/mol Calculation: Amount of moles = Mass of substance/Molar mass n=m/M 5.4 g Benaldehyde is 5.09*10^-2 moles 1.5 g Acetone is 2.58*10^-2 moles According to the chemical equation 2 moles of BA react with 1 mole of acetone. So acetone is in a very slight excess, meaning we will use benzaldehyde to calculate the yield. 2 moles of BA react to form 1 mole of dibenzalacetone, so the moles of BA are divided by 2 to find out how many moles of dibenzalacetone are theoretically possible. 2.55*10^-2 moles of dibenzalacetone And we change the equation from the beginning to find out the mass. Amount of moles * Molar mass = Mass of substance n*M=m This leads to a maximum of 5.97 g of dibenzalcetone, but I had 4.3 g, which is 72% of the maximum yield. (Which shows that I did the round off of the yield wrong in the video... :D ) You could also use the amounts of moles and compare them the same way.
This document gives some information on the preparation of chalcone and their derivatives. www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwi31rzj6P3YAhXGZlAKHWwyBHYQFghBMAI&url=http%3A%2F%2Fcas.bellarmine.edu%2Fchemistry%2Fchem217s00%2FLaboratory%2FChalcone%2520Procedure.doc&usg=AOvVaw1zbRfq4gEiG_Cz3pKUcziB
It is washed with water to remove traces of sodium hydroxide. Recrystallization is always done, because usually the crystals which are formed contain less impurities than before. There are lots of possible side products which are removed by the recrystallization.
Why did you washed the product with cold ethanol in the end? As ethanol has good dissolving ability wouldn't it dissolve the recrystallization product then?
Molar Masses: Benzaldehyde 106.121 g/mol Acetone 58.08 g/mol Dibenzalacetone 234.29 g/mol Calculation: Amount of moles = Mass of substance/Molar mass n=m/M 5.4 g Benaldehyde is 5.09*10^-2 moles 1.5 g Acetone is 2.58*10^-2 moles According to the chemical equation 2 moles of BA react with 1 mole of acetone. So acetone is in a very slight excess, meaning we will use benzaldehyde to calculate the yield. 2 moles of BA react to form 1 mole of dibenzalacetone, so the moles of BA are divided by 2 to find out how many moles of dibenzalacetone are theoretically possible. 2.55*10^-2 moles of dibenzalacetone And we change the equation from the beginning to find out the mass. Amount of moles * Molar mass = Mass of substance n*M=m This leads to a maximum of 5.97 g of dibenzalcetone, but I had 4.3 g, which is 72% of the maximum yield. (Which shows that I did the round off of the yield wrong in the video... :D ) You could also use the amounts of moles and compare them the same way.
Really a good day I ask you another questions What is the role of ethanol in synthesis what is the test to be performed to ensure the effectiveness of the washing of the raw product.
I'd say the ethanol is just to increase the solubility of one or several compounds or intermediates. To find out whether the product is clean a good and simple method might be determining the melting point. More sophisticated methods would be IR or NMR spectroscopy.
The elimination of water is favored in higher temperatures. Maybe keeping the reaction cool throughout the whole synthesis and doing the recrystallization at low temperatures might help.
@@RaExpIn ............Thanks, That is a GREAT IDEA!!!!!!!!!!!!!!!! I should have thought of that myself cause i have done a couple dehydration reactions and i HATE doing them cause i always have to jack up the heat to like 170 C or higher like 300 or 400 C. I still would not have thought of it if you did not just tell me. Those stupid protons that are taken off to make the double bond are so freaking resonated. I was actually thinking the other way...........I was thinking maybe not put any EtOH or NaOH in the pot and just rely on the water to make the enols and hope the water would not dehydrate the alcohols. I mean water is weak and should not be a good dehydrator. If anything it should hydrate stuff...lol. I LIKE YOUR IDEA BETTER THOUGH. I want to do an aldol with acetone to make the beta hydroxy ketone...BUT .. I also want to do an aldol condensation with acetone to make the alpha beta unsaturated ketone. THANKS AGAIN
@@RaExpIn ....Oh my god dude i just spent 8 hours reading the same 3 paragraphs from a hundred different sites. Finally i found the answer............EVERY ONE KNOWS because of the conjugation of the double bond formed it is VERY EASY TO dehydrate and form the double bond. BUT there is a LOT LESS chance if there are not protons in the pot. Meaning no acid or alcohol or any protic compounds. Because with acid in there the hydroxy group can be protonated making it a good leaving group. IF ONLY BASE IS IN THE POT then the hydroxy group can not be protonated and will never be a good leaving group to form the double bond. So without protons in the pot the elimination is BARELY possible BUT IF the base does cause a condensation with a couple molecules and forms a double bond the mechanism has to go through an E1cB mechanism. Another thing that stops the condesation part of the reaction is to use a weaker NON SOLUBLE base like barium hydroxide and put it in a soxhlet so the base is not CONTINUOUSLY in contact with the pot. As long as there are no protons in the pot then HEATING the reaction in a soxhlet will be no big deal. So the deal is.........if you want no double bonds use a weaker insoluble base and use a soxhlet to keep the base from being in constant contact with the pot And have no protons in the pot. And even better if you can do it then distill out your product as it is made, If that is possible. Then of course not only does it shift the equilibrium but then THE PRODUCT can not be dehydrated if it is distilled out as it is made. Of course since your base catalyst is not soluble in the solution of reactants and is in the soxhlet the reaction TAKES A LOT LONGER.
There's two benzene rings and all the double bonds. So, the elections can move over the whole molecule. You can look up delocalization and conjugated double bonds.
NileRed has often uploaded experiments I had on my list for years, but I decided to do them anyways. Mainly, because there is no german version of these experiments. I still really enjoy watching his channel. And my syntheses are usually still a bit different. So, this might happen sometimes.
Dude, the fuck you talking about? I'm not new here, these new youtubers are copying each other just for the views. Its a common thing these days. I have been watching chemistry videos from a very long time ago, even when myst32YT was around. So don't even bother explaining shit to me.
what I mean is, it's easy to complain about a lack of originality if you're standing on the sidelines, not making any content yourself. If Aleksa wants something more original, complaining about other peoples' hard work to produce free content is less efficient than taking initiative and uploading a video themselves.
Not complaining, just stating the obvious. Producing the same content that already exists is just a waste of time. Not trying to be rude. Maybe get inspired by nurdrage, make a video series of obtaining specific chemicals from off the shelf products to make something useful. Maybe explore immersion metal plating? Electro-deposition? There are no videos on that topic.
Since our schools have moved to online schooling and we are doing our organic 2 labs "online", your video helped me understand this much better than my professor's handout!!! Thanks!
Really helpful! Since classes turned online...my teacher has been using these videos to give us an accurate image of it. I think I should give you some love in Patreon!
Amazing, show stopping, iconic
Thank you for explaining yield change when washing I never knew it effected my yield!
Very nice working...well done sir..😊👌👍
Thank you for this
Since our college is now oprate online lecture I was unable to understand this during my journal completion but now after watching this I can do it easily
Thank you 💖
Thank you for posting this, as mentioned previously my college has also moved all classes including labs online. Your video helped me understand the procedure better and thank you for going over the mechanism :)
You're welcome! :)
Thank you so much Sir. I have practicals exams tomorrow and needed to understand this ☺
Love your accent, now I'm addicted to these videos help
Haha! Well... Have fun? :)
so help full👌🏻😇
Please help me !
do you know the first yield?” Before Recrystallize"
What is the recrystallization medium?
can you explain why you use that much amount of benzaldehyde and aceton? I need to use 0,05 mole of benz with the quantity of acetone but i cant figure out. :(
What is the red color when we first add the half of benzaldehyde and acetone in NaOH solvent?. Two days ago, when doing this experiments, i surprised about this. So I wonder what is the red color?
Salut merci pourvédio svp vous pouvez me dire quelle est le but et le principe de cette synthése
Is the same method used to make this commercially, or are there any other ways to synthesis it on a large scale? Also how is Benzalacetone made ?
What it use for?
Thank you very much!
thank you very much for the explanation....
please is that you can help me and give me the semi developed formula of dibenzylideneacetone
yes i enjoy good job
GREAT VIDEO.......GREAT CRYSTALS..........I want to do an aldol condensation between acetone and acetone to make 2_methyl_4_oxo_2_pentanene. And then destroy the double bond with KMnO4 and make pyruvic acid and acetone.
Can I know the melting point of this experiment?
why does the temperature have to be 20-25 degrees? great video thanks!
Can you explain how you got to the Adol product at 2:09 ? Right after the enolate attacks the benzaldehyde
One of the electron pairs of the double bond of the enolate attacks the carbon of the aldehyde group. An electron pair of the negatively charged oxygen in the enolate moves down, which leads to a ketone in the former enolate.
I'll use this video for educational purposes
Thank you so mutch 🥰
Why this method?
keep it up
What is the white cylindrical rotating thing at bottom?
That's a magnetic stir bar. :)
Oh okay. Thanks for clarifying!
What was the purpose of washing the residue with water until its pH became neutral?
gets rid of NaOH which would contaminate your product. you could also use EtOH with some AcOH in it.
what are the reasons as to why it is important to set initial reaction at 20- 25 degrees?
I guess it's due to the possibility that a Cannizzaro reaction might be possible. (Aldehyde in alkaline conditions) And the aldol condensation between acetone molecules is also an option. (Formation of diacetone alcohol)
@@RaExpIn How does it prevent the Cannizzaro from taking place? Does the Cannizzaro reaction involve strong heating?
@@RaExpIn I know I’m quite late, but if the Cannizzaro has a possibility to occur, why does colder temperatures prevent it? Shouldn’t it still continue?
We also performed that experiment
Yield could be increased by adding acetone in parts to a solution of benzaldehyde and alkali.
How do you explain why the percentage yield is not 100%?
It never is. Nothing is 100% quantitative.
Umm can anyone tell me how the yield is calculated?
I already had someone asking this, so here you go :)
Molar Masses: Benzaldehyde 106.121 g/mol
Acetone 58.08 g/mol
Dibenzalacetone 234.29 g/mol
Calculation:
Amount of moles = Mass of substance/Molar mass
n=m/M
5.4 g Benaldehyde is 5.09*10^-2 moles
1.5 g Acetone is 2.58*10^-2 moles
According to the chemical equation 2 moles of BA react with 1 mole of acetone.
So acetone is in a very slight excess, meaning we will use benzaldehyde to calculate the yield.
2 moles of BA react to form 1 mole of dibenzalacetone, so the moles of BA are divided by 2 to find out how many moles of dibenzalacetone are theoretically possible.
2.55*10^-2 moles of dibenzalacetone
And we change the equation from the beginning to find out the mass.
Amount of moles * Molar mass = Mass of substance
n*M=m
This leads to a maximum of 5.97 g of dibenzalcetone, but I had 4.3 g, which is 72% of the maximum yield. (Which shows that I did the round off of the yield wrong in the video... :D ) You could also use the amounts of moles and compare them the same way.
does we take any aldehyde and acetophenone to synthesis different derivatives of chalcone??
This document gives some information on the preparation of chalcone and their derivatives. www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwi31rzj6P3YAhXGZlAKHWwyBHYQFghBMAI&url=http%3A%2F%2Fcas.bellarmine.edu%2Fchemistry%2Fchem217s00%2FLaboratory%2FChalcone%2520Procedure.doc&usg=AOvVaw1zbRfq4gEiG_Cz3pKUcziB
Why adding alcohol in sodium hydroxide solution in starting
Can you tell me reasons for it ??
I'd say its done to decrease the solubility of the product and increase the yield.
Why we use ethanol at the beginning ?
To dilute the compounds and make it easier to control the temperature. Otherwise it might heat up too quickly.
what is the role of washing with iced water
what is the role of recrystallization
It is washed with water to remove traces of sodium hydroxide. Recrystallization is always done, because usually the crystals which are formed contain less impurities than before. There are lots of possible side products which are removed by the recrystallization.
thanks
Why did you washed the product with cold ethanol in the end? As ethanol has good dissolving ability wouldn't it dissolve the recrystallization product then?
In cold ethanol the product is not very soluble.
@@RaExpIn Can we use cold water instead of ethanol?
Thank you for answering by the way 💖
The ethanol is needed to dissolve side products and residual benzaldehyde.
Hello ... Please, how the yield is calculated, or rather how the theoretical mass of the
dibenzalacetone from the mass of reactors
Molar Masses:
Benzaldehyde 106.121 g/mol
Acetone 58.08 g/mol
Dibenzalacetone 234.29 g/mol
Calculation:
Amount of moles = Mass of substance/Molar mass
n=m/M
5.4 g Benaldehyde is 5.09*10^-2 moles
1.5 g Acetone is 2.58*10^-2 moles
According to the chemical equation 2 moles of BA react with 1 mole of acetone.
So acetone is in a very slight excess, meaning we will use benzaldehyde to calculate the yield.
2 moles of BA react to form 1 mole of dibenzalacetone, so the moles of BA are divided by 2 to find out how many moles of dibenzalacetone are theoretically possible.
2.55*10^-2 moles of dibenzalacetone
And we change the equation from the beginning to find out the mass.
Amount of moles * Molar mass = Mass of substance
n*M=m
This leads to a maximum of 5.97 g of dibenzalcetone, but I had 4.3 g, which is 72% of the maximum yield. (Which shows that I did the round off of the yield wrong in the video... :D ) You could also use the amounts of moles and compare them the same way.
Thank you so much
Just had a good day :) You're welcome!
Really a good day
I ask you another questions
What is the role of ethanol in synthesis
what is the test to be performed to ensure the effectiveness of the washing of the
raw product.
I'd say the ethanol is just to increase the solubility of one or several compounds or intermediates. To find out whether the product is clean a good and simple method might be determining the melting point. More sophisticated methods would be IR or NMR spectroscopy.
best
Why product is yellow
because of the conjugation
what is the goal of adding ethanol?
QUESTION...........What if you do not want double bonds on your final product and want the beta hydroxy groups to stay????????????
The elimination of water is favored in higher temperatures. Maybe keeping the reaction cool throughout the whole synthesis and doing the recrystallization at low temperatures might help.
@@RaExpIn ............Thanks, That is a GREAT IDEA!!!!!!!!!!!!!!!! I should have thought of that myself cause i have done a couple dehydration reactions and i HATE doing them cause i always have to jack up the heat to like 170 C or higher like 300 or 400 C. I still would not have thought of it if you did not just tell me. Those stupid protons that are taken off to make the double bond are so freaking resonated. I was actually thinking the other way...........I was thinking maybe not put any EtOH or NaOH in the pot and just rely on the water to make the enols and hope the water would not dehydrate the alcohols. I mean water is weak and should not be a good dehydrator. If anything it should hydrate stuff...lol. I LIKE YOUR IDEA BETTER THOUGH. I want to do an aldol with acetone to make the beta hydroxy ketone...BUT .. I also want to do an aldol condensation with acetone to make the alpha beta unsaturated ketone. THANKS AGAIN
@@RaExpIn ....Oh my god dude i just spent 8 hours reading the same 3 paragraphs from a hundred different sites. Finally i found the answer............EVERY ONE KNOWS because of the conjugation of the double bond formed it is VERY EASY TO dehydrate and form the double bond. BUT there is a LOT LESS chance if there are not protons in the pot. Meaning no acid or alcohol or any protic compounds. Because with acid in there the hydroxy group can be protonated making it a good leaving group. IF ONLY BASE IS IN THE POT then the hydroxy group can not be protonated and will never be a good leaving group to form the double bond. So without protons in the pot the elimination is BARELY possible BUT IF the base does cause a condensation with a couple molecules and forms a double bond the mechanism has to go through an E1cB mechanism. Another thing that stops the condesation part of the reaction is to use a weaker NON SOLUBLE base like barium hydroxide and put it in a soxhlet so the base is not CONTINUOUSLY in contact with the pot. As long as there are no protons in the pot then HEATING the reaction in a soxhlet will be no big deal.
So the deal is.........if you want no double bonds use a weaker insoluble base and use a soxhlet to keep the base from being in constant contact with the pot And have no protons in the pot. And even better if you can do it then distill out your product as it is made, If that is possible. Then of course not only does it shift the equilibrium but then THE PRODUCT can not be dehydrated if it is distilled out as it is made. Of course since your base catalyst is not soluble in the solution of reactants and is in the soxhlet the reaction TAKES A LOT LONGER.
Why is dibenzalaceton yellow?
Hepl me:((
There's two benzene rings and all the double bonds. So, the elections can move over the whole molecule. You can look up delocalization and conjugated double bonds.
Try to oxydate it to p2p
asoy
Mama mia---
Why make videos that are already made by NileRed? Be more original.
NileRed has often uploaded experiments I had on my list for years, but I decided to do them anyways. Mainly, because there is no german version of these experiments. I still really enjoy watching his channel. And my syntheses are usually still a bit different. So, this might happen sometimes.
Dude, the fuck you talking about? I'm not new here, these new youtubers are copying each other just for the views. Its a common thing these days. I have been watching chemistry videos from a very long time ago, even when myst32YT was around. So don't even bother explaining shit to me.
If that's what you want to see, why not step up to the plate and show us how it's done?
what I mean is, it's easy to complain about a lack of originality if you're standing on the sidelines, not making any content yourself. If Aleksa wants something more original, complaining about other peoples' hard work to produce free content is less efficient than taking initiative and uploading a video themselves.
Not complaining, just stating the obvious. Producing the same content that already exists is just a waste of time. Not trying to be rude. Maybe get inspired by nurdrage, make a video series of obtaining specific chemicals from off the shelf products to make something useful. Maybe explore immersion metal plating? Electro-deposition? There are no videos on that topic.