The Periodic Table

02:00

@ringo and @Nicolau I absolutely agree with "LaTeX in titles has always happened and will always happen." And it is not necessarily a bad thing. The biggest problem with it is the mhchem package, as the ce does produce some url slug issues for search engines. See this discussion on meta. [...]

Nicolau Saker Neto

Yeah

And hello Martin

Martin - マーチン

But there are some more issues than that... It breaks the title on any sites that do not have MathJax installed, which I think is the bigger issue, see here and here. Whenever possible, try to make the title with real words only :D

Hello, how are you today?

Have you had a nice weekend?

Nicolau Saker Neto

I'm fine, and you?

Pretty standard weekend for me, but I enjoy staying at home

And yes, I think I spoke poorly earlier trying to make an amusing remark

Martin - マーチン

Sometimes those are the best

Nicolau Saker Neto

I looove staying home, I could see myself being a hikkikomori in an alternate timeline

Martin - マーチン

02:05

Haha ;) I think i get it

@NicolauSakerNeto Japan would therfore be a good home for you ;)

We have a couple of them

Nicolau Saker Neto

Perhaps you read that I almost went there for my Master's degree?

Martin - マーチン

Yes I remember that...

Nicolau Saker Neto

I'd have enjoyed it I think

Martin - マーチン

Now you go to oz, which is i think more of the opposite

I believe there is no way someone cannot enjoy Japan

Nicolau Saker Neto

I suspect I might end up going if at least for a meeting

Since it's so much closer than Europe or the US

Martin - マーチン

02:09

My weekend was awesome, I went to an art event in Tokyo, where I bought a shirt, which says "International Motherf***er" on the front and on the back "Hooray for me and f*** you"

Nicolau Saker Neto

Haha the asterisks

Martin - マーチン

now it works... hahaha

I don't want to swear here...

I find it inappropriate

Nicolau Saker Neto

Professionalism is good

Martin - マーチン

But this time it's an exception, as it is a quoute...

Nicolau Saker Neto

We understand

Martin - マーチン

02:12

It always is, and once you start using strong language, you think more about the language and your rage as opposed to thinking about the argument you would want to make work

Nicolau Saker Neto

I can see that being true

Martin - マーチン

Have you read the chat guidelines, yet? Please weigh in on the discussion!

3

I posted this for all to see, I'd like it to become faq, so we have a general understanding

Nicolau Saker Neto

Looks pretty agreeable

The pinging thing was getting a bit out of hand sometimes

Which is why I rarely do it myself

Martin - マーチン

@NicolauSakerNeto It's all too easy telling somebody to go to some far away place, but making her/him understand is hard

I only use it to reply to a specific post, so that the linking shows up in the transcript

The excessive use was what made me include it.

It is a good feature though...

Nicolau Saker Neto

Useful, certainly

Martin - マーチン

02:19

Yes especially in times where a discussion may go over days, because we are on the other side of the globe, respectively.

Del Pate

04:58

We graduated!!!!! and I know I am late.

@santiago @Martin-マーチン @Freddy @ron @MARamezani

santiago

09:26

lol

-5

Q: Did the Chemistry StackExchange suddenly get a whole lot more interesting?

I enjoy keeping an eye on the 'hot' network questions bar, since they tend to give an interesting cross-section of questions from a dizzying array of areas. Because of this, I've come to know the little favicons for most of the Exchanges quite well, to where I can pick them by sight without even ...

discussion

Martin - マーチン

09:58

Yes we have, @santiago!

santiago

absolutely!

Martin - マーチン

@DelPate Better late than never!

How are you santiago? Good weekend?

santiago

not bad at all, how was your weekend?

Mew

hello

can someone help me

well?

santiago

@Mew just dive in and ask

tschoppi

10:08

Sure @Mew, and hi!

Mew

I was looking up an organic molecule

and I found two different boiling points

I don't know why they are different

chemspider.com/Chemical-Structure.7959.html

-28

but here:

mastersearch.chemexper.com/cheminfo/servlet/…

it is -43

so why are these different?

tschoppi

You mean melting point I assume, not boiling point?

Mew

sorry i mean melting point not boiling point

tschoppi

Well, the easy answer is that they are reported differently because somebody botched an experiment

2

Mew

so which one is botched? I have seen sources that quote both results

tschoppi

10:13

I'd go with the one that has more sources backing it up

the other one is likely to be wrong

might be that it crystallizes in different ways though

Mew

The second link actually is a result of a search I did for molecules with melting points of -28

and it gave me the right molecule, and says melting point is -43, even though i told it to search for those with -28

how accurate are experiments of this nature?

Would the melting point be known with certainty?

tschoppi

I'm not an experimentalist, so I can't comment on the reliability of melting point measurements that are below 0 °C

Martin - マーチン

@mew The melting point reported at chemspider is for 98% chemical: alfa.com/en/catalog/B20790

Mew

what does that mean

spectrumchemical.com/MSDS/TCI-M0178.pdf

^also supports -28

The student I tutor needs an isomer of C5H10O that has melting point of 028

-28

I couldn't find any other isomer that was close except this one

perhaps the teacher has used the incorrect source?

Martin - マーチン

Perhaps s/he did, I'd trust this one: webbook.nist.gov/cgi/…

Is it a theoretical approach or practical synthesis?

Mew

10:28

it's a simple highschool project where the students have to figure out the molecule C5H10O

and they are given melting point is -28

and bp 98

Martin - マーチン

Well, I'd assume that the data is taken from one of the abundant sources

Mew

abundant sources?

Martin - マーチン

pubchem.ncbi.nlm.nih.gov/compound/…

LordStryker

13:06

holla

So apparently Jan Jensen is now a member of our site!

Stack Exchange

13:41

0

Q: On formatting electron configurations

I usually pay a very high attention to the formatting of anything I write, especially to the mathematical notation, because in my opinion it is really important. Of course, the most important thing in formatting is its consistency, and while in principle everyone is free to follow his own persona...

discussion

LordStryker

14:57

\o @Waffle'sCrazyPeanut

Waffle's Crazy Peanut

@LordStryker o/

LordStryker

long time no see. how you been?

Waffle's Crazy Peanut

waffles says Howdy

@LordStryker Exams and stuff. Got rid of them just a few weeks ago :)

LordStryker

Congrats! Any special plans for the summer ?

Waffle's Crazy Peanut

Nope. Stay at home and code the summer away! :P

LordStryker

15:00

Like a true nerd. I'm in a similar boat. Work all summer but its what we enjoy so its all good.

Waffle's Crazy Peanut

Nothing special so far in waffle's life

@LordStryker Yeah! I wish my mom sees in that perspective

user223679

15:17

@Martin-マーチン How was the match?

@Waffle'sCrazyPeanut @LordStryker Hello!

LordStryker

\o @user223679

user223679

@LordStryker What does Stryker mean?

LordStryker

no clue.

I need to change this name

unfortunately I've used it for so long changing the name will confuse some people

Nicolau Saker Neto

Stryker of Mortal Kombat fame?

user223679

@LordStryker How did you come up with it then? :p

LordStryker

15:21

@NicolauSakerNeto kings of chaos

@user223679 blindly

Nicolau Saker Neto

Never heard of that

LordStryker

@NicolauSakerNeto Good. Shameful really I don't even like to admit it :P

@Wildcat Nice meta post btw.

Wildcat

Greetings!

@LordStryker, hmmm. Which one? :D

LordStryker

E. configs

Nicolau Saker Neto

Nice post indeed

I'll try to follow it

Wildcat

15:32

Or, this one on meta. Thanks.

Is bse.pnl.gov/bse working for anyone?

Why sites are down when you really need them? :D

LordStryker

@Wildcat Its down. "Horrible Exception..."

there is a mirror of this site on a european server I believe

Nicolau Saker Neto

Haha a horrible exception indeed

Wildcat

@LordStryker, yes, the same story for me.

And now it works. But slowly.

God bless the Internet!

LordStryker

bse.pnl.gov/bse/portal

working

LordStryker

15:45

ugh I hate it when you try to find a minimum and it keeps opt-ing to a TS with some BS methyl rotation or something

user223679

16:01

@LordStryker You there?

LordStryker

yo

user223679

@LordStryker Does inversion happen only in amines?

LordStryker

From what I can remember from my O-chem days, any atom with a lone pair in a similar configuration can undergo inversion but in the case of the amine, the energy barrier is low enough that it has been observed experimentally. I wouldn't be surprised if another example has been observed experimentally but I can't say for sure.

user223679

@LordStryker Oh. Thanks

LordStryker

Looks like in the case of phosphorus (isovalent with N), it requires much more energy to undergo inversion. See: cuvillier.de/uploads/preview/public_file/2066/9783869551531.pdf

user223679

16:12

@LordStryker Is it a good question for the main site or "too broad"?

LordStryker

Depends on how you word it. I think it would make for a good question.

user223679

@LordStryker Hey, the link you provided answers it! The enrgy barrier aint that low in P. And I assume it increases down the group. So in ideal cases, N gives, others don't.

LordStryker

Glad it was useful :)

@user223679 you should fill out your profile :)

user223679

@LordStryker For the autobiographer badge? ;)

LordStryker

@user223679 So people like myself know who we're addressing

user223679

16:18

Just another high schooler @LordStryker

LordStryker

they teach nitrogen inversion in high school?

40 more to go before i can finally edit questions and answers again

i hate the rep increases upon graduation :\ I understand why they do it but man its hard to let go of certain things you used to have.

user223679

@LordStryker Sort of. Well, we need to know that amines dont give optical activity.

@LordStryker 30 ;)

LordStryker

16:42

No rules about asking for rep in chat yet. @Martin-マーチン didn't include that in his meta post. Therefore... beg for upboats nao!! ^_^

Upboats to da left!

@tschoppi Typical experimentalists...

user223679

@LordStryker Only 5 users have access to moderation tools :o

LordStryker

@user223679 That isn't surprising to be honest. Takes lots of rep to get there. We had plenty more before graduating.

@Martin-マーチン has 2 more edits to go before he becomes 1337

I wonder where @dissenter has been

That guy has asked so many questions and from what I can remember, they were pretty good questions too.

user223679

stackoverflow.com/users/39677/blankman?tab=profile

@LordStryker Look at this guy's question to answer ratio :p

LordStryker

That is quite incredible. I can never think of many questions to ask :\

user223679

@Arpan Hello!

LordStryker

16:54

heya @Arpan

user223679

data.stackexchange.com/chemistry/query/299762/… @LordStryker

LordStryker

nice!

user223679

@LordStryker You there? I have one more question.

LordStryker

@user223679 hit me

user223679

Which is kinetically the most stable allotrope of phosphorus?

Red yellow back or white?

@LordStryker

LordStryker

17:07

Well, P4 is a very stable structure from what I can remember.

I believe the color is white but let me check to make sure

user223679

White and yellow are reactive. Black is thermodynamically most stable and about red... no idea.

LordStryker

Hmmm

well i suppose if we were to consider a SINGLE P$_4$ molecule, it'd be white phosphorus

red phosphorus is polymeric...

so is black

If we are considering n number of P4 subunits, then I would go with black phosphorus

user223679

@LordStryker Lets say a lump of each.

LordStryker

Lets go with black then. Thermodynamically stable at room temp and pressure...

user223679

@LordStryker Kinetically? The answer given is Red. No idea why.

LordStryker

17:15

according to this page that is correct science.jrank.org/pages/241/Allotrope.html

according to this page Black is the most stable chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/…

user223679

> The allotropes of phosphorus illustrate the variations in chemical properties that may occur among such forms. White phosphorus, for example, is a waxy white solid that bursts into flame spontaneously when exposed to air. It is also highly toxic. On the other hand, a second allotrope of phosphorus known as red phosphorus is far more stable, does not react with air, and is essentially nontoxic.

Doesnt mention thermo or kinetic.

@LordStryker Rather, none of the pages mention kinetic/thermo. Black is thermo most stable.

LordStryker

well what do you mean by stable?

thermodynamically stable? kinetically stable? least reactive? stable at room temp?

user223679

Thermodynamic and kinetic stability.

LordStryker

This reference says black phosphorus is the least reactive books.google.com/…

Mann

@user223679 , there's a difference in thermodynamic and kinetic

Thermodynamically , the process of conversion of diamond to graphite should be spontaneous, kinetically its not ^^

user223679

17:21

Thermo--> Black Kinetic--->???

@Mann Yes. I know. My ques is on kinetic. For thermo its black.

Mann

But I think thermodynamically, black is most stable there is least angular strain

wEll for that you need rates of reaction .-.

There is even ambiguity in saying kinetically stable,

Where did you have that question anyway?

user223679

@LordStryker But reactivity depends on both kinetic and thermo factors.

Mann

Yes, but for kinetic factors, you need to consider activation energy

LordStryker

This might help. "Bulk crystals of black P are stable
under ambient conditions for at least a few
months" (from: http://www.pnas.org/content/112/15/4523.full.pdf?sid=d4b76ccd-9c5c-409d-a066-6756a1e4d250)

now find a lifetime for red phosphorus

we all know red phosphorus is used for match heads and those can last years

Mann

They are like measure of kinetic stabilty. More higher the activation energy of intermediate things, lesser the chances for reaction to proceed

Yep haha

Kinetics would depend on pathway of reaction

user223679

17:25

Its better to post it on the main site :p Someone will know some data about it :)

Mann

Thermodynamic you just need reactant and product

user223679

@LordStryker Paywall

LordStryker

Look, when I think of stable I think of (in terms of thermodynamics) lowest free energy. If deltaG is negative, then the more stable it is. The larger the magnitude of deltaG, the more stable it is. kinetics simply describes how fast A -> B

user223679

@LordStryker DeltaG is negative implies spontenietY?

LordStryker

yes

lower free energy to me means more stable however

user223679

17:36

More stable means less spontaneous?

LordStryker

as a computational chemist, lower electronic energy means more stable

so look, if deltaG of A--->B is negative, the process is spontaneous (regardless of how slow or fast the process is) because B is more stable

the more spontaneous, the more stable

user223679

Okay... we are talking about B.

Mann

@user223679 still my favourite case for that is still diamond to graphite :D Although the gibbs energy change is not so large negative number.

user223679

Ya. Fine. Looks correct. @LordStryker . But this discussion of deltaG wont help in kinetic stuff.

LordStryker

9

Q: Difference between thermodynamic and kinetic stability

What is the difference between thermodynamic and kinetic stability? I'd like a basic explanation, but not too simple. For example, methane does not burn until lit -- why?

thermodynamics kinetics stability

user223679

17:40

@Mann The question target the kinetic nature specifically. Your example is perfect as a counter-intuitive example.

LordStryker

To be honest @user223679, nothing is stable at a gazillion degrees Celcius.

its relative

At least that's the answer i'd give. Didn't define a set of conditions? i'll define my own. here you go.

Mann

@user223679 , if you wanna know the kinetic stability of a substance then you must know PATH of reaction, HOW it is converted and TO WHAT is is converted to AND EVERY ENVIRONMENTAL CONDITION.

Like catalyst etc

user223679

@Mann That would render the question useless. Anyway, it looks confusing as kinetics deal with reaction mechanism and we dont know which reaction is being taken as the standard. Or in other words, as @LordStryker said, we dont know the conditions :)

Mann

Exactly

LordStryker

@user223679 generally we'd use room temp and pressure as a reference point. Then from that point on, assuming all things equal, you could simply examine the 'lifetime' of a substance and determine its stability

user223679

17:47

@LordStryker Looks good. But is pure red P used in matchsticks? If yes, then we get our answer.

LordStryker

@user223679 Thats the thing, I don't know for sure

I wouldn't ever imagine it being 100% pure on matchheads

user223679

Time for a new question. And maybe I will ask amine inversion too.

@LordStryker You can answer it based on your half-life theory and we will see what others say.

@LordStryker Do you mind if I post a link to this chat in my question?

LordStryker

I do not mind at all.

user223679

18:20

@LordStryker

0

Q: Which allotrope of phosphorus kinetically the most stable?

I ruled out white and yellow as being quite reactive. Red and black allotropes are both polymeric and comparitively less reactive. Black looks the most stable one thermodynamically. But kinetically, I have no idea whether it should be red or black. The answer provided to me is Red. (Rel...

inorganic-chemistry reactivity allotropes

LordStryker

18:36

Looks good!

Wildcat

19:29

books.google.ru/…

According to this black is the most inert one.

Stack Exchange

23:30

0

Q: Everyday use of "Everyday Chemistry"

everyday-chemisty is a useful way for people to find questions that laypeople might ask about chemistry. It's a bit of a "meta" tag but we can hold (or re-hold) that discussion another time, since I think it does have some utility. It gets abused by new(er) users thinking that it means chemistr...

discussion tags

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