Hi, thanks for all the videos you have posted for A2 chemistry. its good to see how you post all these videos just to help students like my self it is much appreciated!
in reply - I have started teaching A level chemistry this year at an independent school in England :) Your videos not only help the students but also me - always nice to hear from another perspective especially when so well and simply (like as in genius) put.
Brian Ducille That's very kind of you to say so Brian. It's great to hear that the videos are helping fellow teachers as well as students. I'll be making more next year for the new specification so keep watching. Thanks again :)
Hi there MaChemGuy - you have asked for feedback on your videos. Well they are a great support to me in class. We use them in conjunction with Cornell's note taking system to record pertinent facts and your explanations are very clear. So thank you for posting your videos which are proving a valued tool for me to use in class.+
Brian Ducille Hi Brian, many thanks for your feedback. I'm glad you have found the videos useful. Can I just ask I what capacity do you use them? Are you a teacher by any chance? If so, do you work in a UK school and teach A level Chemistry? I'm compiling a report for my Principal as to the impact of the videos and your answers to these questions would be very helpful. Thanks in advance.
I finished the spec quite some time ago thanks to your videos. The only topic I’ve attempted quite a few times and still not fully understood is chromotography I’ve watched your videos, read the books but I just can’t seem to get my head around it . I’ve attempted Questions papers on it but I find myself memorising answers rather than actually understanding what’s going on is there anything you could recommend that I do ?
If HOCH2CH2OH forms the most hydrogen bonds, surely it dissolves in the stationary phase easier? So has a longer retention time than CH3OH? There's obviously a problem in my thinking, any help would be much appreciated
The SP in the question was a liquid alkane and so non polar. Interactions will therefore be via van der Waals forces not H-bonds. The more H-bonding potential, the less interaction and so shorter RT. If the SP had been polar however, it would have had the longest RT. It all depends on the nature of the SP
Hello, great video but can you please tell me how 'forming hydrogen bonds is kind of the opposite mechanism to dissolving to van der waals forces? Thank you!
For a substance to dissolve in another substance they need to be able to interact with each other. Polar molecules dissolve each other by dipole dipole or hydrogen bond interactions and non polar by van der Waals interactions. Just remember 'like dissolves like'
Im a bit confused here sir....i don’t get why c5h12 is more soluble when it can only form van der wal forces.Whereas the alcohol forms hydrogen bond which is the strongest.So wouldn’t alcohol be more soluble in the last example and travel the least
Day dreamer Xxx The stationary phase isn’t water, it’s a liquid alkane. Like dissolves like so the alkane will dissolve best into it due to its ability to form vdw with it. The alcohol will interact the least as it can’t form H bonds with an alkane
I don't understand why longer chain alcohols (also dialchohols) have less interactions because this is the opposite of normal solubility of alcohols????
Have you come across the 'like dissolves like' phrase for solubility? Non-polar molecules dissolve/interact with the non-polar stationary phase by forming van-der Waals forces with it. Polar molecules can't do that as they interact by forming hydrogen bonds. Does that help?
Alastair Grundy When he says they form hydrogen bonds, he means between molecules of themselves, not between the alcohols and the stationary phase. The liquid stationary phase (say a long chain alkane) is not capable of hydrogen bonding, so cannot effectively dissolve the alcohols. Remember 'Like dissolves like'. In this case, it's not so much about the strength of the different interactions but whether or not they are present. If the stationary phase was a substance capable of hydrogen bonding then the order would reverse.
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This is the most helpful GC video I have seen. Thanks with the great work!
Hi, thanks for all the videos you have posted for A2 chemistry. its good to see how you post all these videos just to help students like my self it is much appreciated!
Thank you so much for all your videos!!! You're a star!
Thank you soo much, I actually understand GC now!! :D
Tysm sir!!
You teach so well!! 😊✌
Very straightforward with all essential info. Thanks!
in reply - I have started teaching A level chemistry this year at an independent school in England :) Your videos not only help the students but also me - always nice to hear from another perspective especially when so well and simply (like as in genius) put.
Brian Ducille That's very kind of you to say so Brian. It's great to hear that the videos are helping fellow teachers as well as students. I'll be making more next year for the new specification so keep watching. Thanks again :)
frkn life saver tysm x
This is very helpful!! I can't thank you enough too :)
Great video, very simply explained. Cheers mate!
thank you so much for this video i have been struggling for a while with organic chemistry it really helped
Chuffed it helped you. Thanks for letting me know 😊
Thaaanks! this is the best explanation.
Your video has really helped me! I struggle with chemistry but you just taught it so well, i understand it all. Thank you so much! :)
Very kind of you to say so. Glad the videos help!
This is an absolutely amazing video. Keep up the great work!
Mustafa Aminalhaq Thanks for that. Glad you think so
@@MaChemGuy sir this is such a great, top tier video, thank you. 🤩
What a hero you are
thank you very much for this video it is well explained and benefits me a lot....
Thank you very much, these videos are very helpful
I can't thank you enough :)
Sonil Zaki You did with your positive comment :)
so helpful, thank you!
these videos helped me a lot to understand gc thoroughly. thnx for valuable videos
once again everytime i struggle with chem you save my butt
Glad I’m able to help
Great vid thanks!
Very clearly explanation. Thank you so much.
Lumar Lucena You're welcome. Thank YOU very much
Hi there MaChemGuy - you have asked for feedback on your videos. Well they are a great support to me in class. We use them in conjunction with Cornell's note taking system to record pertinent facts and your explanations are very clear. So thank you for posting your videos which are proving a valued tool for me to use in class.+
Brian Ducille Hi Brian, many thanks for your feedback. I'm glad you have found the videos useful. Can I just ask I what capacity do you use them? Are you a teacher by any chance? If so, do you work in a UK school and teach A level Chemistry? I'm compiling a report for my Principal as to the impact of the videos and your answers to these questions would be very helpful. Thanks in advance.
I finished the spec quite some time ago thanks to your videos. The only topic I’ve attempted quite a few times and still not fully understood is chromotography I’ve watched your videos, read the books but I just can’t seem to get my head around it . I’ve attempted Questions papers on it but I find myself memorising answers rather than actually understanding what’s going on is there anything you could recommend that I do ?
Firmino Becker Where does it break down for you. I’ll try and explain it in a different way for you
If HOCH2CH2OH forms the most hydrogen bonds, surely it dissolves in the stationary phase easier? So has a longer retention time than CH3OH? There's obviously a problem in my thinking, any help would be much appreciated
The SP in the question was a liquid alkane and so non polar. Interactions will therefore be via van der Waals forces not H-bonds. The more H-bonding potential, the less interaction and so shorter RT. If the SP had been polar however, it would have had the longest RT. It all depends on the nature of the SP
Sir, why unknown substances don't have retention time?
great to quickly remind myself
Hello, great video but can you please tell me how 'forming hydrogen bonds is kind of the opposite mechanism to dissolving to van der waals forces? Thank you!
For a substance to dissolve in another substance they need to be able to interact with each other. Polar molecules dissolve each other by dipole dipole or hydrogen bond interactions and non polar by van der Waals interactions. Just remember 'like dissolves like'
Thank you so much 🙇
well explained.
Thankyou !!!
Im a bit confused here sir....i don’t get why c5h12 is more soluble when it can only form van der wal forces.Whereas the alcohol forms hydrogen bond which is the strongest.So wouldn’t alcohol be more soluble in the last example and travel the least
Day dreamer Xxx The stationary phase isn’t water, it’s a liquid alkane. Like dissolves like so the alkane will dissolve best into it due to its ability to form vdw with it. The alcohol will interact the least as it can’t form H bonds with an alkane
Beautiful like always :)
I don't understand why longer chain alcohols (also dialchohols) have less interactions because this is the opposite of normal solubility of alcohols????
i myself dont know why, but it may change the factor of which affects interactivity when it is a longer chain.
with the stationary phase, that is
Thank you.
wow Thankyou soo much this video is soo helpful.
cutiee pie Glad you liked it and thanks!
Thank you
Hey would you be able to explain about polar and non-polar compounds interacting with the stationary phase?
Thank you.
Have you come across the 'like dissolves like' phrase for solubility? Non-polar molecules dissolve/interact with the non-polar stationary phase by forming van-der Waals forces with it. Polar molecules can't do that as they interact by forming hydrogen bonds. Does that help?
Forgot to say that the greater the interaction the longer it takes for the molecule to travel through the column
+MaChemGuy So non-polar molecules will be slowed down the most?
Thank you so much! I watch your videos on a daily basis :)
+Alexxx Exactly! And if the stationary phase was polar, it would be the other way round. Glad you find them helpful :)
Alexxx hi
Why when hydrogen bonds are formed does it interact less? Since hydrogen bonds are stronger
Alastair Grundy When he says they form hydrogen bonds, he means between molecules of themselves, not between the alcohols and the stationary phase. The liquid stationary phase (say a long chain alkane) is not capable of hydrogen bonding, so cannot effectively dissolve the alcohols. Remember 'Like dissolves like'. In this case, it's not so much about the strength of the different interactions but whether or not they are present. If the stationary phase was a substance capable of hydrogen bonding then the order would reverse.
This is good but I need the method for it and so far no website has found it any suggestions?
Chemguide
my exam is in 45 minutes. thank you
how'd it go
is it true.
thank you for vidio
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top bloke
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