Hi... I'm from India... today I was just searching for problem solving regarding acidity n basicity...I found ur video very helpful...thank you so dear...god bless you... it's so nice teaching...I pray to God... to get such an amazing teaching...thnk u once again
@@RoxiHulet thnk u so much... I hv subscribed ur channel for further update...I hope it will be highly useful for me... thank you so much once again mdm...I will continue to keep watching it 👍
Chlorophenols have a lower pka than phenol. Wouldn't chlorophenol be a stronger acid then phenol. The chlorine group pulls electron density by induction.
@@alessandrac1940generally, acidic strength is directly proportional to both -M and - I, and halogens have dominant inductive effect (they have mesomeric too but -I is more dominant) that's why chlorophenol should be more acidic than phenol ig.
Chlorine atoms can also donate electrons through resonance (one of the lone pairs falls in and makes a double-bond with the carbon atom). That said, I think the inductive effect might win out and make 4-chlorophenol a stronger acid (have a lower pKa) than phenol at 11:30. But I've seen conflicting numbers when I looked it up and it seems their levels of acidity are very close.
I know that methyl (ch3) groups are ED, but just cause the textbook said so... i'm not really sure how since there is no lone pair or negative charge on the carbon.. i guess cause it's not electronegative?
Yeah, that's pretty much the explanation. It's not very satisfying, though! Most textbooks do not use the term "electropositive" and it is not something typically taught in Gen Chem when we teach electronegativity. However, electropositivity is an actual thing :) and it is essentially the opposite of electronegativity. Electropositive atoms (carbon) are electron donors.
Hi miss or professor sorry i don't know what they call teacher in USA, do you have any place i can message you because i have question and i really want answer for it , thanks 😊😊😊
Halogens are electronegative and withdraw electron density in that capacity. However, they also donate electron density via resonance. Their contribution to resonance is important to this particular type of problem.
@@RoxiHuletother sources are telling me that their EWE is greater then their contribution to resonance and so it takes priority making its carboxylate hydrogen more acidic then benzoic acid
You're going to do awesome!! Here are my tips... (1) The questions aren't in order of difficulty, so skip around and find the easy ones first. Then work on the harder ones you feel confident about. Save the sketchy ones for last. If you run out of time, you want to run out of time working on problems that you might not have gotten correct anyway. (2) There isn't a penalty for guessing, so if you start to run out of time, just start making guesses. Answer every question. (3) Remember that the average student gets about half the questions correct, so don't freak out when you look at the test and feel like you don't know how to do a bunch of them - it's normal! I'm crossing my fingers for you!!
O stands for orbital - a negative charge on an sp hybridized atom is more stable than a negative charge on an sp2 hybridized atom, which is more stable than a negative charge on an sp3 hybridized atom. This is only true if the atoms are all the same type, and have equal resonance and induction.
you actually saved my life tonight thank you queen
Anytime!! 😘
Hi... I'm from India... today I was just searching for problem solving regarding acidity n basicity...I found ur video very helpful...thank you so dear...god bless you... it's so nice teaching...I pray to God... to get such an amazing teaching...thnk u once again
You are most welcome
@@RoxiHulet thnk u so much... I hv subscribed ur channel for further update...I hope it will be highly useful for me... thank you so much once again mdm...I will continue to keep watching it 👍
Thank you for this. You literally have saved me tonight
Yeah these videos are awesome! I took ochem a long time ago, but still use it a bit and Roxi's playlists are amazing review material.
You're very welcome!! Happy to help!
Chlorophenols have a lower pka than phenol. Wouldn't chlorophenol be a stronger acid then phenol. The chlorine group pulls electron density by induction.
I was thinking the same thing
yeah the induction from chlorine is stronger than the mesomere effect normally?
@eknoorsingh3260 ok! Glad I'm not the only one who is confused. I know that cl- is obviously negatively charged, but it is EN.
@@alessandrac1940generally, acidic strength is directly proportional to both -M and - I, and halogens have dominant inductive effect (they have mesomeric too but -I is more dominant) that's why chlorophenol should be more acidic than phenol ig.
Yes chloro phenol stronger acid than phenol because of negative inductive effect
I thought Chlorine had a strong pull on electrons because it was electronegative.
Chlorine atoms can also donate electrons through resonance (one of the lone pairs falls in and makes a double-bond with the carbon atom). That said, I think the inductive effect might win out and make 4-chlorophenol a stronger acid (have a lower pKa) than phenol at 11:30. But I've seen conflicting numbers when I looked it up and it seems their levels of acidity are very close.
For the first one, doesn’t the lack of aromaticity cause there to be no resonance, thus making the molecule more basic?
Excellent question and observation, and yes - the non-aromatic compound in problem 1 (triethylamine) was ranked the strongest base.
Your explanation is totally awesome mam❤❤❤ from Bangladesh
Thanks a lot 😊
I know that methyl (ch3) groups are ED, but just cause the textbook said so... i'm not really sure how since there is no lone pair or negative charge on the carbon.. i guess cause it's not electronegative?
Yeah, that's pretty much the explanation. It's not very satisfying, though! Most textbooks do not use the term "electropositive" and it is not something typically taught in Gen Chem when we teach electronegativity. However, electropositivity is an actual thing :) and it is essentially the opposite of electronegativity. Electropositive atoms (carbon) are electron donors.
ok thanks that kinda makes sense to me now@@RoxiHulet
In good books the explanation is sp3 so electron density more distortable so its weak inductive
Hi miss or professor sorry i don't know what they call teacher in USA, do you have any place i can message you because i have question and i really want answer for it , thanks 😊😊😊
I am confused this question but I understood it completely through your understanding, thanks mam
That's fantastic! I'm so glad that my video helped you get it figured out!
God bless your heart
halogens are electron withdrawing! but much less withdrawing than nitro groups.
Halogens are electronegative and withdraw electron density in that capacity. However, they also donate electron density via resonance. Their contribution to resonance is important to this particular type of problem.
@@RoxiHuletother sources are telling me that their EWE is greater then their contribution to resonance and so it takes priority making its carboxylate hydrogen more acidic then benzoic acid
well explained, thank you!
You're welcome!
Thank you so much for this video god bless
You're very welcome!!
Really helpful. Thank you
Thank you for the help! It was a bit distracting when the train came by, but overall a good video.
train went crazy
Thanks.
Taking ACS tomorrow pray for me
You're going to do awesome!! Here are my tips... (1) The questions aren't in order of difficulty, so skip around and find the easy ones first. Then work on the harder ones you feel confident about. Save the sketchy ones for last. If you run out of time, you want to run out of time working on problems that you might not have gotten correct anyway. (2) There isn't a penalty for guessing, so if you start to run out of time, just start making guesses. Answer every question. (3) Remember that the average student gets about half the questions correct, so don't freak out when you look at the test and feel like you don't know how to do a bunch of them - it's normal!
I'm crossing my fingers for you!!
you sound like the amoeba sisters
What does the O in ARIOA stand for? 🥹
O stands for orbital - a negative charge on an sp hybridized atom is more stable than a negative charge on an sp2 hybridized atom, which is more stable than a negative charge on an sp3 hybridized atom. This is only true if the atoms are all the same type, and have equal resonance and induction.
@@RoxiHulet ohh alright!! Thanks a lot