Say one thing.

What would u write .

Yes. I guess. There was an SE question on that too.

Yes you are right. But I dont understand how.

@Abcd In generality,yes it is a phase transition.. But it has two rate constants associated with it.. Suppose you want to talk about only one.. U make a question on that.. Then i will consider that reaction only

Those days when our teacher didn't teach us thermo and we had to learn ourselves. I learnt so much.

@YUSUFHASAN No this was a JEE question. Not mine.

See the answer.

@Abcd Maybe because I have seen it before so I subconsciously said that.

@PolarBear its talking about Chemical vs Physical process. Not phase trans as a term for allotrope connversion.

Also, predict sign of $\Delta S$ (I was able to do this :D)

> The conversion of ferrite into austenite is a phase transition, so it should formally be classified as a physical change.

@Abcd allotropy will be considered a phase change cuz the two reactions(forward and backward) can enter such a state where their rates become equal.. That is...activation energh required becomes negligible... So u can take it at equilibrium

@PolarBear Standard state has zero enthalpy

not entropy.

I was being dumb

@YUSUFHASAN Nice

That is what answer states..And yes.. Entropy is only zero at zero Kelvin

@YUSUFHASAN Which answer r u referring to now??

I think this it is more like p block question

Yep.

Think and answer.

Sure?

Wrong!!!

Its less than 0.

Red is more ordered as it is polymeric

Never mind.. It was deleted.. And no.. Entropy change is ofcourse negative

White is haphazard

question was white to red ice

Oh, shit (':

I should study CS. Anymore questions?

Okay.. Seems @PolarBear didnt read the question

Isn't red more reactive ??

No

No.. Red is polymeric

due to angle starin

white is more reactive

@AdvilSell No

angle strain in white

Bro.. White has angle strain

@AdvilSell That's white

BTW reactivity is not the right explanation of Entropy!!

It has to do with degree of randomness.

Ikr

@Abcd Yep.. Consider the number of free states avaiilable to each form for oscillation of bonds..

@PolarBear Oh okay , yes

Trashhhhhhh

Trashhhhhh

Trash is trash

Sorry

Make x, y and z axes.. And make the phosphorous form.. And try to see where you can stretch bonds without compromising on the the bond angles too much.. Thats a mathematical way to do it..

no dude why go to that much detail

it was a match the column.

@YUSUFHASAN That's very hard to imagine

Cant we just say red is polymeric and hence more ordered = less degree of randomness

Or.. Just keep that a polymeric form will be more free to move .. Cuz white will have lesser free states due to constrictions in movement completely along z axes

But I think that it should be more than zero now

@PolarBear Still.. Thats the proper way to do it

Because nature wants randomness

And white is nice reactive ready to increase randomness

girl

white -> red

Why will it be reactive if it doesn't do randomness

Oh but wait, we heat it for daysss

*We* heat it

@PolarBear No.. Randomness is anyway a deprecated form of entropy study in higher science.. Idk ehy it is still used in India... The true way is to consider free states of transition like i told

There.. Your idea will fail

@YUSUFHASAN Correct. We are still kids though. Give kids explanation please

@YUSUFHASAN Randomness = entropy B.S. !!

@PolarBear Just think of it this way.. When u shake a slinky and the wooden frame of a kite with one hand.. Where do you expect to see more random movement?

In fact.. Where do u think most of the movement will occur?

@YUSUFHASAN slinky

Slinky=red form

Cyclopentene + NBS then alc KOH then CH3MgBr

Kite= white

@YUSUFHASAN How?

@YUSUFHASAN So S should increase? Right? No?

wasnt the question red to white?

@PolarBear is the reaction a phase transition ??

@YUSUFHASAN white to red

Someone help

After KOH it will be anti aromatic ring?

No no sorry

Then.. I dont know how to givr this in terms of randomness.. Sorry

It will be cyclodiene

And then CH3 will abstract H to make it aromatic

@PolarBear no the anion is aromation hence the anion

Got it.

@YUSUFHASAN @PolarBear is the sign of Entropy change +ve ??

@AdvilSell i cant seem to find the data.. Can you look it up? For red to white or vice versa.. Entropy change?

@YUSUFHASAN Yeah , sure , can you pls. expalin how excatly do you all concluded that it's a phase transition ??

pls. , I read your chat but couldn't get it

@AdvilSell allotropy will be considered a phase change cuz the two reactions(forward and backward) can enter such a state where their rates become equal.. That is...activation energh required becomes negligible... So u can take it at equilibrium

@AdvilSell Its a jee question and white -> red is given negative.

@YUSUFHASAN Can you define phase transition

@YUSUFHASAN oh I see , just a last question can we conclude that the $\Delta H$ of the rxn White ----> red is Negative as it must be exothermic ??

@Abcd

Have Mains 2 Admit cards been released?

@Abcd Nope , on 20th march

@AdvilSell Red is more stable so yes

In energy diagram it will be below white.

That's why $\Delta H = -ve$

That's my non mathematical reason

Yeah then the answer is -ve , the sign of $\Delta S$

@AdvilSell Sorry but your Mains 1 percentile was?

@Abcd it was really low 97.XX

@AdvilSell OK

Hey avnish kabaj hi

@Abcd well I can explain the sign of entropy now . do you want it ??

He comes in between and leaves

@AdvilSell No. I am satisified w/ my reason.

@AdvilSell Did you understand why $\Delta H = -ve$ ?

@Abcd Oh...okay , thanks I do understand ,I just wanted to confirm

HI

NCERT P block 1st year page 315. Ionization enthalpy.

Last line

"increase in size of atom" doesn't make sense to me

@Abcd @YUSUFHASAN @AdvilSell

@PolarBear Moshi Moshi

@Dante Wassup?

Dinner ;p

my doubt is right above ^^^^

I'd rather prefer discussing it after dinner, is it ok for you?

it'll be 10 mins

Okay... Lemme first read that part where ur doubt is

ok

@Dante As size of atom increases.. The outer most shell of electrons will move farther away from the nucleus.. So pulling effect of nucleus on the valence electrons will decrease... So it's easier to ionise them.. Hence IE decreases

@Abcd A phase transition is literally when a substance changes its state from one form to the other under a set of conditions of temp. and pressure.. Now generally,this "state" is solid,liquid or gas,because for interconversion to be possible,changes must be sufficiently reversible with minimum requirement of extra external energy(I.e. activation energy)... This is always true for these solid to liquid to gas changes, which is why we categorise them under "physical changes", and call them

"Phase transition".. It just so happens that allotropic change of phosphorous fits the bill.. So it was also grouped under this set of reactions as it satisfied the required conditions... Maybe we can call it a degenerate case of phase transitions

Problem here is the somewhat ambiguous term "state"

mixture of oil and water has liquid state but 2 phases

@Abcd There is as such no interconversion going on here.. It is insoluble... The activation energy to cause an interaction is too high

@Abcd That phase is different

Yeah... A phase has to differ on the basis of intermolecular forces... Solid,liquid and gas have that... A mixture of oil and water will just sit there with a boundary b/w them with some constant value of intermolecular forces.. Mixing them is energetically costly... And most of the energy provided to them will cause evaporation of different components at different times.. So nothing doing here

back

@Dante Got it,then?

back, now reading it XD

@YUSUFHASAN Yes, but read the read the complete sentence.

slight increase from Sn to Pb consequence of...blablabla.. and increase in size of atom.

Don't they mean the opposite?

Or do I have language problems? I'm not sure XD

No.. Simply because as d and f orbitals shield poorly.. So the nuclear pull increases quite a lot ,dominating increase in size.. Its like, the increasing size can only help in matters when shielding supports it.. If the reduction in effective nuclear charge isn't significant.. Then the valence orbitals will also be pulled in towards the nucleus.. First thing to see is the effective nuclear charge,that governs size.. Not the other way round

OH, ok.

@YUSUFHASAN Another one page 317 Problem 11.6 second point.

Didn't understand it.

Whose sock is ignite?

Avnish Cabbage

Captain Qooeschan

@Dante dπ backbondings are weak

Oh, right.

Thankss!

@PolarBear What makes you believe it's a sock?