JEE Chemistry Club

McSuperbX1

02:40

Whats gonna happen if I add water to PhCCl3? Acyl halide or Carboxylic acid? Why?

Dante

Depends on conditions, partial hydrolysis - acyl halide, complete - acid.

McSuperbX1

02:59

Oookay.

drake01

04:29

Hello

McSuperbX1

05:49

Benzaldehyde + Br2/CCl4 --> ?

Morrison suggests alpha halogenation

however alpha halogenation (as said in the book) happens for ketones (which is only acid or base catalyzed).

Abcd

@McSuperbX1 How can you do alpha halogenation here?

McSuperbX1

IDK morrison says that

Abcd

@McSuperbX1 page number?

McSuperbX1

I'm referring to the solutions of morrison and boyd

the question is itself on: page 817

Q1 part d.

OH NO

not benzaldehyde!

phenylacetyldehyde im sorry :(

Abcd

@McSuperbX1 Acetaphenone?

McSuperbX1

05:56

No

phenylacetyldehyde.

the book says nothing on alpha halogenation on aldehydes - however I have the official solutions book for morrison and boyd called "Study Guide to Organic Chemistry"

by the respected authors themselves

the study guide says alpha halogenation happens no reasons given

Abcd

@McSuperbX1 Are you sure the solvent is CCl4?

Because alpha halogenation happens in acidic medium.

McSuperbX1

Yep. It says "Br2/CCl4"

it happens in both acidic/basic mediums. but for ketones as far as i know.

Is this an error?

However.. if you look at the acid catalyzed method of alpha halogenation; you will see enolization takes place. And in phenylacetaldehyde a very stable enol could form.

@Abcd Don't get it?

I have another question - when should one think about enolization anyway? like wherever one can form a really stable enol via resonance - should one go for it OR something else is needed?

Q3) Does ketone - ketone aldol condenation happen? my teacher suggest not to think about ketone - ketone aldol condensation.

Abcd

@McSuperbX1 My page 817 has NMR Spectrum

McSuperbX1

I have 6th edition. Pearson.

Abcd

@McSuperbX1 it happens.

Oh I have 7th

Tell me the chapter name

McSuperbX1

06:03

Sec.

Chapter 21: Carbanions 1 - PROBLEMS (last exercises of the chapter)

Q1

Abcd

MY chapter 21 is organic photochemistry :(

McSuperbX1

look for carbanions 1

is it there?

Mine is the non-indian-author version

Another question lol Q4) One should not think about ketone-ketone aldol condensation in a container which contains an aldehyde and a ketone - right?

Abcd

@McSuperbX1 yes donor is ketone and acceptor is aldehyde

McSuperbX1

@Abcd How about aldehyde-aldehyde?

I think aldehyde-aldehyde and aldehyde-ketone will compete

Abcd

@McSuperbX1 Yup, can't comment without data.

McSuperbX1

06:10

Did you find carbanions 1 in your book?

Abcd

not there

McSuperbX1

damn

Well what do you think would happen phenylacetalhyde + Br2/CCl4?

I think that maybe enol may form (can't say how?) and then things happen similar to acid catalyzed alpha halogenation of ketones

Abcd

@McSuperbX1 benzylic halogenation in presence of light

McSuperbX1

No mention about light/UV

Abcd

Idk then.

McSuperbX1

06:12

The enol that may form would be pretty stable. in resonance with the phenyl ring too

Abcd

06:24

Silly but still: Why is SO3- less deactivating as compared to SO3H? @YUSUFHASAN

YUSUF HASAN

@Abcd Because the O- present will be more reluctant to pull electrons from the ring as compared to O-H part of SO3H due to bond polarity of O-H bond..(like COO- is less deactivating than COOH)

Abcd

@YUSUFHASAN Hmm ryt, ty.

YUSUF HASAN

@McSuperbX1 I read the transcript for the preceding chat, and I don't really understand what your doubt is... Do you want to know the conditions for acid-catalysed enolization,or alpha halogenation,or what?

Please paraphrase your misgivings succintly once again

McSuperbX1

Does alpha halogenation on phenylacetaldehyde happen with Br2/CCl4? Yes/No and why.

YUSUF HASAN

06:40

Alpha halogenation on phenylacetaldehyde would require the formation of an enol initially for the substitution of Br to occur anywhere... CCl4 is by no means going to promote enolization as it's not even polar,let alone acidic or basic... So no, alpha halogenation by the usual mech is certainly not happening here...

McSuperbX1

My following question: The resulting enol (if I assume enolization happens somehow) - is pretty stable. So - basically; acid catalyzed enolization is the only way to form enols?

YUSUF HASAN

06:53

Nope:Base catalyzed enolization also exists,and the fundamental difference in that acid catalyzed enolization is faster than base catalyzed

@McSuperbX1

McSuperbX1

@YUSUFHASAN Hm alright. I believe there is an error in my book then. thanks for bearing with me.

Abcd

@AdvilSell @Dante on which question were we stuck few days back? The one which we decided to leave....some carbanion-wikipedia etc thing??

Dante

¯\_(ツ)_/¯

Akari

07:13

Why isn't C the answer??

Correct option is A

McSuperbX1

Question: Is it necessary to use the salt of the exact same acid as present in the anhydride (in context to Perkin's reaction)?

Nevermind - found my answer here: chemistry.stackexchange.com/questions/100722/…

Akari

@Abcd you there?

Abcd

@Akari back.

Akari

@Abcd the question above McSuperbX1's last message

Abcd

@Akari It should be C.

Akari

07:26

Okay. Then my book must have an error. Thanks!

Dante

07:51

@Akari Is the question you asked in PSS a JEE main question?

Akari

@Dante nope it's from advanced

Dante

Hmm, ok.

McSuperbX1

08:23

prnt.sc/nafft5 What happens when I would add dilute acid to this compound?

I think nothing's gonna happen?

Dante

nothing ig, if it's dilute

@Abcd

NCERT 1st year part2. Page 348, crystallization.

"If the compound is highly soluble in one solvent...."

Didn't understand that part.

How is crystallization carried using 2 solvents?

Dante

08:43

Does anyone else have any idea?

Abcd

08:54

@Dante It's self explanatory actually.

Dante

I didn't get it. What are they actually doing using those 2 solvents?

Abcd

They will crystallise it and impurity will go to the solvent it likes more.

Dante

hmm

Dante

09:30

In which chapter does "The radius of curvature of the trajectory" come? Projectile motion, RBD, circular motion or what?

Abcd

09:43

@Dante circular

@Dante The procedure is simple, just find the accln perpendicular to velocity and equate with $\dfrac{v^2}{R}$ ... R gives radius of curvature.

@PolarBear @Dante Are they enantiomers or identical?

Dante

looks identical to me

Abcd

@Dante In second pic, exchange Cl and CH3 (allowed coz of symmetry) ... Then keep mirror in plane of first pic... you will get 2nd modified pic....

so why are they not enantiomers

Dante

Flip the right ring you'll get left one, complete superposable

(Flip matlab not ring-flip, just turn it)

McSuperbX1

turn the ring towards yourself (top part towards you, bottom part away from you) so same structures

Abcd

OK

McSuperbX1

09:50

I like questions like this because I suck at them do you guys have more?

Or maybe a reliable source to practice such questions

Dante

@Abcd Wait, I didn't understand how exchanging them is allowed???

Abcd

10:02

@McSuperbX1 MSC

@Dante From symmetry? Does it make any difference? Because relative positions of every other group remains same?

McSuperbX1

@Abcd ? msc ?

Abcd

@McSuperbX1 Balaji's MS Chauhan

McSuperbX1

@Abcd Oh - my teacher told us to staaay the hell away from these books xD

Abcd

@McSuperbX1 which coaching are you from?

McSuperbX1

@Abcd fiitjee

Dante

10:04

@Abcd I don't think so. It does make a difference. You'll get enantiomer instead!

Abcd

@Dante Oho yes

@McSuperbX1 It's (MSC being unsolvable etc) a myth. But dont buy now, it's too late.

Dante

No, it's not late.

It's never late.

Abcd

OK...

McSuperbX1

@Abcd He didn't say its unsolvable - he said the book has wrong concepts in use.

Abcd

there are like 200 qs per chapter.... if MC superb has time he can buy it

@McSuperbX1 He is wrong. Maybe his own concepts are flawed!

McSuperbX1

10:06

I doubt that

Dante

@Abcd He doesn't need to solve all of them...100 in each chapter and he will be near to perfection in JEE organic.

Abcd

@McSuperbX1 You can't comment becoz you didn't try the book.

McSuperbX1

I do

and he has shown wrong concepts in the book

and told us to not refer to it again

Abcd

@McSuperbX1 Please show me too

@McSuperbX1 ^^^

McSuperbX1

Please dont take this personally. Even if a book has some flaws does not mean its a waste.

Abcd

10:08

@McSuperbX1 I know but now I am curious no.

I want to see the conceptual flaws.

I know there are some mistakes here and there but v few.

McSuperbX1

I would have to look - do not have the time on my hand

Wrong concepts as in minor issues which gave wrong answers - no huge problems ofcourse.

Abcd

@McSuperbX1 last year's topper of SE solved it only... And got ~700 rank.

Dante

gaurang?

Abcd

Yes

@Dante BTW Nomenclature came in mine, is it coming in all papers? just curious.

Dante

I saw 1-2 papers, idk shit in nomenclature.

McSuperbX1

10:17

@Abcd No further comments from me!

Abcd

@Dante What did @AdvilSell solve btw?

Dante

What? For organic? idk

He has MSC.

I'm freaked out man ;_;

What if it's a bad day tomorrow.

I'm confused what to revise also!

Advil Sell

@Abcd Msc

@Dante Quick question : what is Kraft's temperature ?

Dante

Temp at which miscelles are activated

I guess

Abcd

@AdvilSell Temperature above which Micelle frmation can take place

Advil Sell

10:31

@Dante Correct

@Abcd Yeah ik

Abcd

@AdvilSell K I thought it was ur doubt.

Dante

Phew, I remember this, had studied 4 months ago XD. I'm planning to study surface chem and chem in everyday life in car tomorrow ;_;

No time now.

Any other question?

quizzz

YUSUF HASAN

I have solved HP.. And have a pretty good idea of MsC... I feel that HP is way more fun to solve and has more thinking required than MsC.. But MsC also does it's job well for JEE.. So it's really a matter of perception

@Dante Which adsorption dye helps to identify silver halides?

Dante

Idk ;_;

Options?

YUSUF HASAN

Ummm.. Eosin... Tryptophan... Fluorescein.... Basel

Dante

10:36

Nope, no idea.

What's the answer?

YUSUF HASAN

Look in applications of adsorption in ncert.. It is fluorescein majorly and also sometimes eosin... Tryptophan is an amino acid... Basel is sthg i just made up XD

Dante

Oh, ok.

"Basel is sthg i just made up" Reminds me of 3 idiots

damnit, surface chem is sooo huge!

PolarBear

Fluorescein, Avnish had once posted that in this group too.

Akari

11:07

Does $CH_3CH_2D$ count as ethane?

Avka

$\require{mhchem}\ce{CH3CH2D}$

I don't think so

I'm tired of reading Chem ncert

Any GMP questions @PolarBear

Akari

@Avka so all the names of hydrocarbons are valid for $\require{mhchem}\ceH$ not $\require{mhchem}\ceD$

Avka

Yeah

An iupac name is supposed to identify/represent one single compound

D is not H

So they must have different names

Akari

@Avka Yeah right. That makes sense. Tnx a lot

PolarBear

@Avka I have many, but i didn't try them the second time so it would be silly to post them

You could always head over to PSS.

Avka

11:26

@PolarBear you could just say the question number

I have gmp

Everyone does

PolarBear

I can post them easily. Nvm.

I have a trick for phone

Oh wait, first the one in PSS

It's very simple I guess

@Avka I have 17-18 edition

Do they have decimal type in latest one btw? Anyone?

Avka

@PolarBear same hoti hai

I had 16-17

It's same as the 18-19

Which I got last month

PolarBear

@Avka Questions are same but question numbers aren't same

Dante

Hi! In some paper there was diffraction + interference combined question, remember which one?

Jan main

PolarBear

@Dante some 11 paper

11th first

Dante

11:31

Oh, okay, Thanks!

Avka

@PolarBear don't calculate the frequency which will be produced from the Mike at 4s

Calculate it for the sound that reaches you

PolarBear

Here, $v = 4 × g = 40$. Now, by Doppler effect, $f_{app} = \dfrac{320 × 1000}{320 + 40} = \dfrac{8000}{9} ≈ 888$

Avka

Lmao

Why did you ask this

PolarBear

Answers not that

It's 894.75

I think it has something to do with the accelerating case

Avka

1 min ago, by Avka

Calculate it for the sound that reaches you

PolarBear

11:33

I don't know what

Avka

2 mins ago, by Avka

@PolarBear don't calculate the frequency which will be produced from the Mike at 4s

PolarBear

What does that mean?

@Avka The speaker will produce the same frequency

@Avka How's that done? Doppler, right.

Avka

Transmission of sound isn't instantaneous

Doppler those deer pehle

Lagao

Not at 4s

PolarBear

So I have this formula for that one too

Dante

@YUSUFHASAN

PolarBear

11:35

But that didn't work because I heard that even that formula is jugaad

Formula

Dante

Any trick to solve the question if they ask colour of d block ions?

PolarBear

$f_{app} =\dfrac{2vf²}{2vf - a_s}$

Dante

Like, anything related to wavelength and number of unpaired electrons.

YUSUF HASAN

First.. See electronic configuration... If it is d(0) or d(10).. It is white

Dante

yeah

YUSUF HASAN

11:37

Then.. U must have performed practicals in class 12 in school,right? @Dante

Avka

@PolarBear

Dante

State board practicals are bullshit (at least in K'taka)

Avka

Apply Doppler at 3.777 seconds

PolarBear

Here

@Avka Why at that time exactly?

Dante

But yes, we did salt analysis (13 salts) and volumetric analysis

Avka

11:39

The wave takes time to reach you

It's not instantaneous

$$ 5t^2/320 + t = 4$$

PolarBear

@Avka Don't we take that into account in the Doppler formula?

Avka

@PolarBear frequency is low and distances are not given

So it's given you have to ignore

PolarBear

@Avka This is the time taken by the wave to reach us?

Avka

@PolarBear $$5t^2/320$$

Is the time taken to reach us

And $t$

McSuperbX1

prnt.sc/naihgh What happens at step 2? Step 1 gives Alpha bromo ketones.

Avka

11:42

Is the time at that moment

YUSUF HASAN

Okay... Well, do you know the colors of common ions like Co3+(pink).. Mn2+(buff pink).. Fe2+(green, remember iron vitriol).. Fe3+(brown).. Cu2+(blue,remember blue vitriol)... And such?

Avka

So total time is 4

YUSUF HASAN

@Dante

Dante

ha?

PolarBear

@Avka The questions says at $t = 4$

So that's absolute time.

Advil Sell

11:43

@Avka Yeah that gives the answer

PolarBear

Ahh

Got it @Avka

Smart avka. Cool.

YUSUF HASAN

@Dante Do uk those colors i just listed?

PolarBear

Thanks @Avka

That's why it's a GMP question.

Dante

Ah, didn't read that.

Avka

Welcome

Dante

11:45

@YUSUFHASAN Ok, knew 3 of them didn't know Fe3+ and Co3+

YUSUF HASAN

Basically... It's more than enough for mains the ones i jzt listed.. Mainly cation colors are for advanced

PolarBear

@Dante Read NCERT

Dante

Oh, ok

YUSUF HASAN

Jzt don't forget to check d0 and d10 there first

Dante

yes

I just found a question in my old paper error list, colour in some d block elements is ......

Answer was "charge transfer"

not d-d transition

PolarBear

11:49

KMnO4

Example

Dante

Oh yes, remember reading that.

And I remember reading reference about charge transfer in NCERT somewhere, do you know where it is?

PolarBear

Good luck for tomorrow @Avka and @Dante

Chill and do well

Dante

Thankss

PolarBear

@Dante reference?

YUSUF HASAN

@Dante Thats an entire concept.. Look at this if u want rn or tmrw

Dante

11:52

Where is it in NCERT? Do you remember?

@YUSUFHASAN No! No time to study NCERT+ now.

All the best @Avka @AdvilSell !

YUSUF HASAN

Charge transfers occur in certain complexes.. MLCT and LMCT are two major types in our scope

PolarBear

Oh advil has tomorrow too, all the best to you too @AdvilSell

@Dante Sorry, I don't.

YUSUF HASAN

ATB to all! @Dante @Avka @AdvilSell

Dante

Oh, okay.

@YUSUFHASAN Thankss

Advil Sell

Thanks All , Also Best luck Both of you @Avka @Dante

YUSUF HASAN

11:55

@Dante There is a reference to that in the either the colors section in coordination compoundsor in KMnO4 in d block.. But im not sure

Dante

Ok, lemme search,

Akari

@Dante Page 253 --> Yellow box has some reasons listed

Avka

Thanks guys

Dante

@Akari Thanks!

Avka

Best of luck to @AdvilSell and @Dante

Akari

12:01

All the best @Avka @AdvilSell and @Dante

Avka

Thanks

Advil Sell

Thanks Guys !!

Dante

Thanks everyone

Dante

13:30

resonance.ac.in/answer-key-solutions/JEE-Main/2019/…

15th one

Isn't water formed in combustion in vapor state?

Akari

@Dante This was the paper in my slot, and gah, I also assumed water to be in vapour state. See this for a probable answer, but I am not sure.

Dante

¯\_(ツ)_/¯ Not gettin it.

But ok, liquid state, that's all I need to know for tomorrow.

Akari

Do you know about ordinary (I am not sure if this was the exact word) state?

Dante

Does that mean state at STP?

Akari

No. The state for which $\Delta _f$ is 0

Dante

13:41

Oh yes, I know that

Ok, I got the insight

McSuperbX1

Any important reagents like Tollen's, fehling, benedict, lucas, brady's for JEE advanced

anything im missing?

Dante

Thanks @Akari!

Akari

@Dante I found the word. It isn't known as ordinary state, but the standard state.

Dante

I see, couldn't revise chemical thermodynamics apparently ;_;

McSuperbX1

baeyer's reagent works only with double/triple Carbon-carbon bonds right?

Akari

13:45

No prob. Just remember those basic formulae, and they'll most probably give the values of R too so that won't be a problem either. All the best!

McSuperbX1

would C=O bond work?

Dante

@Akari Yeah

@McSuperbX1 no

PolarBear

13:59

Giving these? @Abcd @Avka @Jasmine

Abcd

@PolarBear Is it worth it?

PolarBear

That's why I am asking here

I have heard that MyPat tests have errors. True?

Abcd

I am planning to give Archive in Test format from day after tomorrow.

@PolarBear Absolutely

PolarBear

Oh, then I'll not give.

Abcd

@PolarBear Didn't you see in JEE Main test which I gave 230 ---> 194. So many errors.

PolarBear

14:01

I have infinite papers to last lifetime

@Abcd Ah yes that

Esha Manideep

14:16

What does T_A and T_B mean in RTPF ppr2 physics 3 ??? @Abcd

@PolarBear @AdvilSell anybody ?

PolarBear

I don't understand as well.

Akari

@Abcd @PolarBear @AdvilSell @YUSUFHASAN @Dante @Avka are we going to have a paper discussion in the near future?

23 hours ago, by Advil Sell

@Abcd Well I have a idea for this feature , whenever we all decide to do a paper we can hold this for discussions ...Just an Idea tho.

Dante

I'll write RTPF tomorrow afternoon.

Akari

Don't you have your mains tomorrow?

Dante

It's in the morning.

Akari

14:29

Ohkay. I meant when everyone(at least some) attempt the same paper and discuss

Advil Sell

@EshaManideep I think (As per discussion with Abcd) that it's the maximum kinetic energy of the electron

Dante

Yeah, almost everyone has attempted it, only me and advilseller are left

Abcd

@EshaManideep It's a misprint I checked solutions

It's meant to be $T_A - T_B = ....$

@EshaManideep T_A stands for maximum KE

@Akari @Dante @AdvilSell @PolarBear What do you say about JEE Advanced 2006 ppr on 13th???

Akari

@Abcd Yup. I vote in favour

Dante

okay (not sure though)

Akari

14:33

@Abcd btw you mean paper 1 or paper 2 or both?

Abcd

@Akari As you wish I am OK with any option

Dante

1+2 is better

Akari

I'd say one paper for now?

Dante

We have to train our minds in that way.

Akari

Okay that's fine too

Advil Sell

14:36

@Abcd I am in , But 1 paper only , But are old paper beneficial ??

Abcd

@AdvilSell You seriously think they r not beneficial???

Advil Sell

@Abcd Nope , I am just asking

Abcd

@AdvilSell Y not both??

Advil Sell

anyways I am in :D

@Abcd I would rather give one paper and do some other questions , inspite of giving 2

Avka

They are having weekly full day tests at kalu

Anyhow I'll be focusing on revision first

PolarBear

15:09

I'm not writing tests. Need to complete practice first.

Esha Manideep

@Abcd Oh. Thanks ! These are not as tough as AITS

Abcd

@EshaManideep Maths was easy but did You find the chem easy?

Esha Manideep

Yeah. Could do the first ones pretty quickly.

Tried one integer answer too. It was easy too

I got CD

Abcd

@EshaManideep Great! It was hard for me.

@EshaManideep Yeah, but where is it given?

Esha Manideep

It's in NCERT

Dante

15:15

Don't spoil the paper -_-

Esha Manideep

Somewhere around raoults law

PolarBear

15:27

Math room someone

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