Yusuf Hasan

general recent conversations

Problem Solving Strategies

General chat for high school physics. For MathJax see meta.sta...

Yusuf Hasan

Dec 23, 2024 18:47

@JohnRennie Hi, random question - I have recently started listening to the Bee Gees. Do you remember them at their peak if you did listen to them back in the day? I find their music quite enchanting :-)

Yusuf Hasan

Jan 4, 2024 16:38

@S.M.T look up statquest linear regression on youtube

Yusuf Hasan

Jan 4, 2024 13:20

@S.M.T In the case of dy/dx you are looking at the response of the y variable when you vary the x variable. Vice versa for dx/dy. If on a certain line dy = 2*dx then it is obvious that dx = 0.5*dy. Just a matter of what you consider as the independent (the one that responds) and dependent (provided as input) variable.

Yusuf Hasan

Jan 4, 2024 13:06

@S.M.T What are "x" and "y-axes" other than a pair of mutually perpendicular lines? Mostly a naming convention

Yusuf Hasan

Jan 4, 2024 10:14

@KavinIshwaran Even without pka/pkb values. Aqueous media is best suited for ionic salt solutions as they rapidly solvate in water. the right hand side is forcefully dissolving NH3 in a covalent gaseous form. Left side contains readily solvated ions

Yusuf Hasan

Dec 31, 2023 05:32

As an example: PCl5 distorts axially in response to repulsions. Hence the 5 sp3d hybrid orbitals do not remain equivalent. Since for the same value of principal quantum number, s orbitals have the lowest energy followed by p and d, hence it redistributes the percent s character towards the equatorial plane. You can imagine this as the axial bond pairs shift away from the central P, so it redistributes to bond pairs closer to P. Net result is energetic stabilization

Yusuf Hasan

Dec 31, 2023 05:25

@KavinIshwaran That is not due to the JEE. In any other polyhedral geometry there is a possibility for bond distortions (mostly elongation) in response to repulsive bond pairs. That corresponds to an overall bond energy optimization towards a local minima in accordance with Bent's rule. We don't have this luxury in the diatomic case since it has only one bond

Yusuf Hasan

Dec 28, 2023 20:53

@KavinIshwaran chemistry.stackexchange.com/questions/117380/….

Yusuf Hasan

Dec 25, 2023 13:11

@KavinIshwaran Sure. The book I have referenced (Arrow Pushing...) contains a few other reactions like phosphorous disproportionation from your syllabus (cross reference from the NCERT don't try to read everything). I suggest spending 10-15 mins trying out mechanisms for major reactions and skimming through the book just to get a rough idea. This will help immensely to create a logical impression in your mind. Don't spend a lot of time on trying to completely sketch out the mechanism tho

Yusuf Hasan

Dec 25, 2023 13:05

@KavinIshwaran See if the approach in these answers seems helpful.

Yusuf Hasan

Dec 25, 2023 13:04

A: Why is chromate stable in basic medium and dichromate stable in acidic medium?

I will be using an approach which has been enlisted in the following book for answering this question: Arrow Pushing in Inorganic Chemistry ;A Logical Approach to the Chemistry of the Main-Group Elements The preface of the book says: The approach: These reactions represent important facets of th...

Yusuf Hasan

Dec 25, 2023 13:04

A: Why is Aluminium oxide amphoteric?

I will be using an approach which has been enlisted in the following book for answering this question: Arrow Pushing in Inorganic Chemistry ;A Logical Approach to the Chemistry of the Main-Group Elements To start off, please go through my answer to this question: Why is chromate stable in basic m...

Yusuf Hasan

Dec 25, 2023 13:02

Hello :)

Yusuf Hasan

Dec 25, 2023 12:58

This may help ease the memorizing pain for reactions to a more logical approach. Random physical properties like molecular weight density etc. unfortunately :/

Yusuf Hasan

Dec 25, 2023 12:56

@KavinIshwaran One tip for IOC: Just once try to make arrow pushing mechanisms for the major NCERT reactions (that's mostly what's part of JEE syllabus anyway). You can see a few examples in my SE answers. No one is going to ask these mechanisms, and you might not get to the final product completely. But just the process of trying it out will inadvertently commit the reaction to memory

JEE Chemistry Club

For Mathjax see: chemistry.meta.stackexchange.com/questions/89/…...

Yusuf Hasan

Jun 23, 2024 15:51

@GauravSaiMaddipati Join it. The course doesn't matter anyway beyond circuital branches and MnC

Yusuf Hasan

May 1, 2024 09:04

as you pointed out even that NCERT line is not completely correct

Yusuf Hasan

May 1, 2024 09:04

Maybe it's a typo or maybe the more worrying part could be they are using the terminology wrong

Yusuf Hasan

May 1, 2024 09:03

at the very least reactants and temperature will be needed

Yusuf Hasan

May 1, 2024 09:03

They should clearly define (1) reactants (2) conditions (heated reflux or chilled) (3) how long is the reaction run for (depending on that it will be addition or condensation)

Yusuf Hasan

May 1, 2024 09:01

Even 2nd one is problematic. How do you know the cross product will be major or minor if neither reactants nor conditions are provided? Products are different under themodynamic and kinetic control

Yusuf Hasan

May 1, 2024 09:00

Then this is in the broadest of sense incorrect. Can be easily challenged

Yusuf Hasan

May 1, 2024 09:00

@HarjotDhillon What is the source of this question? NCERT and coachings are notorious for mixing up "aldol addition" and "aldol condensation" (never mind referring to self and cross products).

Yusuf Hasan

May 1, 2024 08:56

@HarjotDhillon

Yusuf Hasan

May 1, 2024 08:56

Q: Why cyclohexane-1,4-dicarbaldehyde does not give aldol condensation?

I was recently came to know as a fact that cyclohexane-1,4-dicarbaldehyde does not give the aldol condensation reaction in spite of possessing α-hydrogens. I was told that this is due to steric reasons, but I am trying to come up with a more specific reason, which does not require prior knowledge...

Yusuf Hasan

May 1, 2024 08:56

This is really a question of inconsistent semantics. Read this answer for more clarity

Yusuf Hasan

Apr 25, 2024 18:04

@HarjotDhillon Not a major contributor as Ag+ is a not very electron rich. But yes a similar dpi - pi* interaction similar to CO may take place with Ag and CN as well. Probably would consider Fajan's rule to be more at play here chem.libretexts.org/Courses/Johns_Hopkins_University/…

Yusuf Hasan

Apr 24, 2024 07:57

@HarjotDhillon You are correct that HCN is a weak acid. Therefore, the reaction itself will be slow without a catalyst. However to whatever extent, CN- WILL be generated and the pathway used will be a conventional substitution from the carbon end. AgCN will be extremely negligible to begin with. There is no real "blockage" to producing CN- ions with HCN as there is with AgCN. At best you can expect a mixture which will tend towards the nitrile as dissociation increases via thermodynamic control

Yusuf Hasan

Apr 3, 2024 10:38

Learnt about the JEE Main difficulty level fiasco. Sorry for those caught up in this, hope that the next slot turns out to be more fair :/

Yusuf Hasan

Feb 19, 2024 09:56

It's mostly related to how the solvation works out: chem.libretexts.org/Bookshelves/Organic_Chemistry/…).

Yusuf Hasan

Feb 19, 2024 09:54

@Swan polar protic solvents generally favor SN1, while polar aprotic solvents favor SN2 generally

Yusuf Hasan

Feb 18, 2024 16:39

No problem. Rate comparison is actually a difficult job, but there are a few fundamental ideas that tie together various common reactions (substitution elimination acid-base) including POLM

Yusuf Hasan

Feb 18, 2024 14:02

also this link: masterorganicchemistry.com/2011/04/12/…

Yusuf Hasan

Feb 18, 2024 14:00

@Swan Go through this link to understand a related concept: the principle of least nuclear motion masterorganicchemistry.com/2012/05/21/…

Yusuf Hasan

Feb 18, 2024 08:05

and intra-electronic repulsions, it actually ends up becoming a stronger base than iodide, meaning that generating it would be that much difficult.

Yusuf Hasan

Feb 18, 2024 08:04

@Swan Simply put: leaving group tendency is more of a kinetic barrier than a thermodynamic one. This also makes sense: the solvation of F- is but a small part of the process; what's more important is generating the intermediate easily (which is an energy-consuming process requiring bond breakage). The solvation will only help in compensating for this rate-determing step as the rate constant for SN1 is rate = k [R-LG]. Another special caveat with F- is that due to it's small size

Yusuf Hasan

Feb 12, 2024 12:22

@Swan are you aware of kinetic vs thermodynamic control?

Yusuf Hasan

Nov 30, 2023 08:52

@HarjotDhillon Pro tip: try to populate this room with atleast 5-10 aspirants (preferably from different coaching) so that this is actually helpful and you get access to different questions

Yusuf Hasan

Nov 30, 2023 08:49

@Mithoron @BuckThorn Are you participating in this group now? I thought no one from the main Chem SE participated in JEE prep questions

Yusuf Hasan

Nov 30, 2023 08:47

Hey is this room back? I thought it was done for :-)

Room for आर्यभट्ट and Yusuf Hasan

Yusuf Hasan

Jul 7, 2023 18:27

@आर्यभट्ट Ok so please give me a en elaborate detailed description

Yusuf Hasan

Jul 6, 2023 20:12

@आर्यभट्ट Can you ask him to connect with me directly?(my LinkedIn profile is present in my bio)

Yusuf Hasan

Jun 23, 2023 08:04

Hence when I got a chance to pursue time series analysis I decided to go with the same.

Yusuf Hasan

Jun 23, 2023 08:03

Not really no, I was always a computational chemist so had a decent understanding of the math and programming part. My last project at UW Madison was also on machine learning applications in statistical mechanics

Yusuf Hasan

Jun 23, 2023 08:02

@आर्यभट्ट No he is a faculty at Sorbonne, I left the Wisconsin project last year

Yusuf Hasan

Jun 23, 2023 05:01

ctanujit.org/members.html (Number [2] PhD and MS thesis supervision)

Yusuf Hasan

Jun 23, 2023 05:00

@आर्यभट्ट Kindof flipped XD

Yusuf Hasan

Jun 23, 2023 05:00

@आर्यभट्ट last year, MS thesis

Yusuf Hasan

Jun 21, 2023 19:20

Here now if you're around

Yusuf Hasan

Jun 21, 2023 19:20

@आर्यभट्ट Ah yes yuvraj/jackrod now I recall