The Periodic Table

user34388

4:00 PM

@orthocresol I thought hybridization is a lie...

This also fails to explain why having a Ph group replacing the H makes it more stable

like PhCC- is more stable than HCC-

user116211

@user34388 It's not a lie ;(

orthocresol

um, phenyl is electron-withdrawing?

user34388

To set things right first - hybridisation is only a mathematical process, a human construct. It does not involve any physical movement of electrons. Therefore hybridisation cannot "happen" in any sense. Trying to make hybridisation happen is like trying to make a half-empty glass "turn" into a half-full glass. — orthocresol Sep 9 at 4:39

user116211

@user34388 Where was it written as lie?

user34388

@ortho seal How does Ph make it more stable?

@MAFIA36790 a construct

user116211

4:02 PM

@user34388 So?

user34388

@MAFIA36790 a construct isn't real

user116211

So, how can it be a lie?

user34388

what.... i'm not into philosophy

let's just say i was wrong.

Can anybody explain to me how phenyl being electron-withdrawing stabilizes C#C- ?

user116211

When a theory contradicts tested hypothesis, then it's false; it's a lie. Just because it is a mathematical concept, doesn't mean it is a lie.

user34388

@MAFIA36790 my fault

orthocresol

4:04 PM

@Wildcat Well, there is a fair bit of QC stuff that I just upvote as well. I don't understand most of it but I just trust that you guys know what you are doing. Like this chemistry.stackexchange.com/questions/31358/…

One day I will try to learn it, but that time has not quite come yet :)

user34388

Does the phenyl group somehow increase the s character of the sp orbital?

orthocresol

MOs are also a construct

we cannot solve the SE for many electron systems

so that is the best we can do, and it works for us, so we accept it.

getafix

Everything is a construct

We are in the matrix

we just haven't been offered the blue and red pill yet ;)

user34388

Look, I was wrong, ok?

@ortho seal Has the SE for H2 been solved?

orthocresol

also, EWG means inductive effect

not as far as i know, in any case, even H2+ which was "solved" invoked born-oppenheimer, so that is not even a full solution

if i remember correctly

user34388

4:10 PM

(pretending to understand) I see

getafix

@user34388 basically we most often can't obtain nice analytic expressions.

user34388

@getafix I see

getafix

However, a few approx. make the problems more tractable

the idea behind born oppenheimer is that the motion of electrons and nuclei can be separated...

so the total wavefunction can be written as a product of an "electronic" and a "nuclear" wavefunction

user34388

I see

pentavalentcarbon

@getafix I think they're in high school

getafix

4:14 PM

of course if you need more details you should ask someone who is smarter than I am..lol

Oh i see..

orthocresol

@pentavalentcarbon That never stopped us from telling them that hybridisation is a lie.

user34388

@pentavalentcarbon look, your high school isn't my high school

orthocresol

I think we say it a bit too often..

getafix

@user34388 what is that supposed to mean?

user34388

@ortho seal in what aspect is hybridisation a lie?

pentavalentcarbon

4:16 PM

I suppose I'll be quiet now...

orthocresol

Lie algebra

In mathematics, a Lie algebra (/liː/, not /laɪ/) is a vector space together with a non-associative multiplication called "Lie bracket" [ x , y ] {\displaystyle [x,y]} . When an algebraic product is defined on the space, the Lie bracket is the commutator [ x , y ] = x y − y x {\displaystyle [x,y]=xy-yx} . Lie algebras were introduced to study the concept of infinitesimal transformations. Hermann Wey...

user34388

@getafix that my high school does not even teach orbitals.

...

getafix

HAHAHAHAH

Wildcat

@user34388 not a big deal, since they don't exist. :D

user34388

@Wildcat I see

orthocresol

4:18 PM

@Loong, are you there?

getafix

I always pronounced it as "Lee" algebra though

Loong

@orthocresol ?

Wildcat

@getafix which is the correct pronunciation.

getafix

oh okay lol

orthocresol

@Loong I just wanted to tell you I hate everything of Atkins.

getafix

4:19 PM

I just felt like my whole life had been a "lie"

Loong

@orthocresol aha

orthocresol

@Loong You know, his books are the only popular science books in my library.

Wildcat

@getafix Lie is a Norwegian surname.

orthocresol

He donated free copies to the library.

Wildcat

Atkins is not that bad, in fact.

getafix

4:20 PM

@orthocresol I know how you feel.. :/

@Wildcat not that good either

orthocresol

(Don't take me too seriously. I still use his textbooks.)

getafix

but I guess I got used to his style..

orthocresol

I'm just afraid of ever meeting him (I had the opportunity to last year)

getafix

I do too....don't really have a choice since my instructor uses it

Loong

@orthocresol In physical chemistry, we had no choice.

getafix

4:21 PM

I supplement it with Donald Mcquarrie

orthocresol

@Loong Atkins used to teach thermodynamics, until he retired several years ago

I believe it was in 2007.

user116211

@orthocresol Did you get his real class!!

getafix

I have actually wondered what he would be like in an actual lecture

Loong

I also used a German book by Gerd Wedler, which has good thermodynamics.

orthocresol

@MAFIA36790 Nah, I started uni in 2014 ;)

user116211

4:25 PM

For Thermodynamics, lectures by Fermi is the best, I have seen so far.

orthocresol

@MAFIA36790 Any more discussion and I risk revealing my real identity, so I will stop here :D

getafix

I like studying more advanced topics in Thermo/Stat Mech or QM from physics texts though

user116211

@orthocresol sure. I like ambiguity ;))

user116211

@getafix they are indeed physics.

getafix

yeah i know.

orthocresol

4:28 PM

@MAFIA36790 I am quite sure that if one really wants to, they can easily find out who I am.

user116211

For adv. Thermo, the version of Caratheodory really thrilled me.

orthocresol

But oh well..

Loong

@orthocresol I guess, our German translation of the physical chemistry book by Atkins was from 1996.

orthocresol

@Loong The thermo lecturer who succeeded Atkins says that the earlier editions were better

user116211

@Loong Wait, I thought there is only an English version...

pentavalentcarbon

4:29 PM

@orthocresol You're white, fuzzy, and live somewhere cold. Duh.

orthocresol

And since he added Julio de Paula, the quality dropped

@pentavalentcarbon My SE profile tells you all about my location anyway

pentavalentcarbon

Near the North Pole, that helps me.

user116211

@pentavalentcarbon ;P

pentavalentcarbon

I also found you in my copy of the Merck Index when I was looking up chloroform earlier...

user116211

Apart from Mart, we are all anonymous ;P

user34388

4:34 PM

0

Q: Would magnesium and calcium hydroxide undergo a single replacement reaction?

Can calcium hydroxide react with magnesium (if given sufficient activation energy) to produce magnesium hydroxide and calcium, in the same way that NaOH + $\ce{Mg} \ce{->} \ce{Mg(OH)2} + \ce{Na}$ ? Or, is calcium's electronegativity (or some other factor) prohibitive of this?

Does anyone actually know this lol

looks easy

pentavalentcarbon

Those are both pretty insoluble, if I remember correctly.

user34388

@pentavalentcarbon nobody said the environment must be aquatic...

and limewater is slightly soluble

pentavalentcarbon

The implication is usually an aqueous environment.

> Calcium hydroxide, Ca(OH)2, is sparsely soluble in water (1.5 g/L at 25 °C[1])

orthocresol

hmm, actually google doesn't turn up anything revealing for "orthocresol"..

so i am not that discoverable..

user34388

@ortho seal it returns the wiki page for me

pentavalentcarbon

4:44 PM

I think that's you.

Wildcat

@orthocresol is it good or bad?

user34388

@pentavalentcarbon No, he is @ortho seal

Wildcat

@pentavalentcarbon deanonimized!!!111 :D

orthocresol

@Wildcat I don't benefit from anybody knowing who I am, anyway. :)

@pentavalentcarbon Literally melting right now then...

pentavalentcarbon

Speaking of books, the Merck Index is actually extremely nice.

I never use it but I'm glad I have it.

orthocresol

4:46 PM

user34388

@pentavalentcarbon what is the compound in your icon?

pentavalentcarbon

@user34388 masterorganicchemistry.com/2010/08/27/…

user34388

@pentavalentcarbon ...

!!img/methanium

Chemobot

No result found.

user34388

Methanium

In chemistry, methanium is a positive ion with formula CH+ 5, namely a molecule with one carbon atom bonded to five hydrogen atoms and bearing a +1 electric charge. It is a superacid and one of the onium ions, indeed the simplest carbonium ion. Methanium can be produced in the laboratory as a rarefied gas or as a dilute species in superacids. It was prepared for the first time in 1950 and published in 1952 by Victor Talrose and his assistant Anna Konstantinovna Lyubimova. It occurs as an intermediate species in chemical reactions. The methanium ion is named after methane (CH 4), by analogy with...

pentavalentcarbon

4:48 PM

I am meant to be the undergraduate mistake, not the actual molecule.

Wildcat

@orthocresol degrees Fahrenheit?

user34388

@pentavalentcarbon the undergraduate "mistake" is an actual molecule

pentavalentcarbon

@user34388 Not when you're in high school or undergraduate organic chemistry it isn't.

user34388

@pentavalentcarbon the education system is a failure

orthocresol

@Wildcat Celsius

pentavalentcarbon

4:49 PM

I disagree.

Wildcat

@orthocresol over +30 and a rain? :O

orthocresol

@Wildcat All year round, no less!

user34388

@pentavalentcarbon I approve your disagreement.

Wildcat

@orthocresol Do you live in tropics? :O

orthocresol

@Wildcat Only during holidays :)

Staying in the North pole all year round is a little cold. Also the polar bears are dangerous

Wildcat

4:53 PM

Well, not close enough... :(

user34388

Aug 17 at 11:36, by Leaky Nun

So my education is bullshit.

orthocresol

That's cold

user34388

Aug 17 at 11:37, by DEAD

@LeakyNun Heh, you should've drawn that conclusion much earlier.

orthocresol

In Oxford, it's still only 15-20 degrees

Then again, Oxford is pretty far south already, I suppose.

user34388

@orthocresol ... I thought you were referring to "so my education is bullsh*t"

Wildcat

4:55 PM

@orthocresol winter is coming! :O

user34388

@pentavalentcarbon DEAD disagrees with you

pentavalentcarbon

@user34388 That is an incredibly poor way of viewing things.

@user34388 I'm ok with that. Most people disagree with me.

orthocresol

@pentavalentcarbon +1

user34388

@pentavalentcarbon Look, orbitals are not taught in my school

pentavalentcarbon

@user34388 That is only looking at an individual tree in the forest, to use a crappy analogy.

orthocresol

4:56 PM

@Wildcat Indeed.. But it is coming late, it seems. Summer came late as well, this year. Very weird..

user34388

@pentavalentcarbon look, i'm not serious lol

user116211

@orthocresol Oxford has a good climate.

pentavalentcarbon

@user34388 Sarcasm doesn't translate well on the internet, which is why our enzyme friend sounds weird most of the time.

user34388

@pentavalentcarbon enzyme?

pentavalentcarbon

@user34388 He's RuBisCo now.

user34388

4:58 PM

right

what was he?

orthocresol

@MAFIA36790 Oxford is actually a really nice place, I'm lucky to be there.

pentavalentcarbon

He was DEAD.

user116211

@orthocresol ;))

user34388

is DEAD an enzyme?

user116211

@user34388 google

pentavalentcarbon

4:59 PM

Diethyl azodicarboxylate

Diethyl azodicarboxylate, conventionally abbreviated as DEAD and sometimes as DEADCAT, is an organic compound with the structural formula CH3CH2O2CN=NCO2CH2CH3. Its molecular structure consists of a central azo functional group, RN=NR, flanked by two ethyl ester groups. This orange-red liquid is a valuable reagent but also quite dangerous and explodes upon heating. Therefore, commercial shipment of pure diethyl azodicarboxylate is prohibited in the United States and is carried out either in solution or on polystyrene particles. DEAD is an aza-dienophile and an efficient dehydrogenating agen...

> sometimes as DEADCAT

:(

user34388

...

orthocresol

@MAFIA36790 Apart from the hordes of tourists! In summer there's just tons of them...

user34388

@pentavalentcarbon where does "CAT" come from?

Wildcat

@pentavalentcarbon :O

orthocresol

It's basically like a foreign invasion.. the sidewalks are full so you have to walk on the roads..

pentavalentcarbon

5:00 PM

@Wildcat :O

@user34388 Must be the carboxylate part. Never heard of that before.

user34388

@pentavalentcarbon that's creative

Wildcat

@user34388 CArboxylTe, probably.

user34388

@Wildcat thanks

Wildcat

CArboxylaTe, or CarboxylATe :D

user116211

@orthocresol ohh.

user116211

5:05 PM

@orthocresol O.o

user116211

Anyways, @ortho, did you visit Cambridge any time?

orthocresol

@MAFIA36790 Quite a few :)

I have a good friend there.

user116211

@orthocresol You need Trump now!!

user116211

@orthocresol Ah ;))

orthocresol

@MAFIA36790 I voted leave and I am a UKIP supporter.

user116211

5:07 PM

@orthocresol stares at Ortho

user116211

But I respect your opinion.

orthocresol

@MAFIA36790 ;) I'm not.

Politically, Oxford (and Cambridge) are a really small bubble.

If you look at the referendum results, for example.

user116211

@orthocresol Oxbridge, as is popularly called ;)

orthocresol

And even the 2015 general election

Most people here think that UKIP is the devil's spawn.

user116211

Anyways, @ortho, have to go back to my study...

orthocresol

5:09 PM

Ah, ok, I'm going to sleep soon anyway :)

user116211

@orthocresol no comments

orthocresol

Good luck.

Loong

Yes, the “lowest sum” method works most of the time. But it does lead to wrong answers sometimes, that's why I'd rather cooperate on propagating the correct way, rather than support wording that suggests that the “lowest sum” is correct. Check the “Don't sum locants!” article by Dr. Ian Hunt, Department of Chemistry, University of Calgary, to see clear examples of when the lowest sum can lead to wrong answers for questions. I believe it should never be used, even if it leads to right answers sometimes. — Rok 28 mins ago

user116211

Good night all o/

Loong

Why does this user preach to the choir and still tries to teach me about the wrong “lowest sum of locants” rule, although the question isn’t even related to this rule?

orthocresol

5:11 PM

@Loong Maybe he was just too enthusiastic about finding out the truth.

Loong

hm

user34388

@orthocresol you always edit anything that floats on top lol

just a link from any comment makes you edit

!!img/tricyanomethane

Chemobot

user34388

this is very acidic although the acidity comes from the C-H bond...

which is what shocks me

pentavalentcarbon

Why would that surprise you?

user34388

5:18 PM

@pentavalentcarbon because i've never seen C-H acids that are considerably acidic

more acidic than carboxylic acids...

God, this is a strong acid...

pentavalentcarbon

Chemistry is weird. I remember a paper from a few years ago where they made a thorium or thallium complex with 11 bonds.

user34388

the electron-withdrawing effect of cyano is quite strong...

or is it just resonance

pentavalentcarbon

The first, not the second

user34388

why not?

pentavalentcarbon

I suppose you could make that argument but they're both going to be involved.

user34388

5:22 PM

@pentavalentcarbon I think the resonance is strong with that one... but is resonance enough?

basically every atom of the ion is involved in the resonance

which is something I haven't seen before...

pentavalentcarbon

Again, it's probably a combination of both.

I couldn't say one over the other unless you presented a set of similar compounds where you systematically replace the cyano groups with something else and examine the pKa.

user34388

@pentavalentcarbon Why is -CN electron-withdrawing? Sorry for stupid question

pentavalentcarbon

It's electron deficient due to some empty pi orbitals that can be filled.

user34388

wait

empty pi orbitals?

Which orbital is empty?

pentavalentcarbon

@user34388 What the hell is that?

user34388

5:27 PM

@pentavalentcarbon hybridization and AO overlap of hydrogen cyanide

yellow and green are p orbitals

pentavalentcarbon

Looks more like I took some psychedelic drugs and tried to do chemistry.

user34388

...

pentavalentcarbon

6

Q: Cyanide ion non-bonding/lone pair?

Where's the lone pair on the cyanide anion in this MO diagram? In the traditional Lewis picture there are two lone pairs on the cyanide ion. In the MO diagram though there appear to be no non-bonding orbitals that are populated ... Also how come there appear to be two sigma bonding orbitals...

inorganic-chemistry

user34388

pentavalentcarbon

That's a much better picture.

Sorry I was making fun of the other one, just very, uh, odd.

user34388

5:29 PM

I consider the first picture much better than this one

pentavalentcarbon

I disagree, too many bright colors with too much going on.

user34388

@pentavalentcarbon Same question: which pi-orbital is empty?

@pentavalentcarbon at least the orbitals overlap

pentavalentcarbon

I might be wrong about the empty pi orbital, let me actually read up on it.

pentavalentcarbon

5:41 PM

Yes, I'm wrong, it's an empty $\sigma_{2p_{z}}$ bonding orbital.

Or, half-empty for the radical.

Loong

@orthocresol no, his last (now deleted comment) was too much

At least, I have got a nice Disciplined badge.

orthocresol

6:03 PM

@Loong o.o I missed it

Loong

6:13 PM

It doesn't matter. He didn't like my answer; he probably didn't really read it. He insisted on talking about another topic that is not related to the question and that has already been explained in another linked answer, which he didn't read either. After his last rude comment, I deleted my answer and disengaged.

Jan

@Rubisco Oh.

orthocresol

@Loong oh well... It happens. ):

Jan

Damn, I can't find recently owner-deleted answers in the 10k-tools, can't find @Loong's recently deleted post D=

orthocresol

That last line of his self-answer is real passive aggressive, haha

Jan

> The last line of his self-answer is deleted, haha

^ fixed that for you ;)

Loong

6:26 PM

@Jan Yeah, even I cannot see my answer in the "Recently Deleted" list.

Jan

But it's okay, I just found it xD

Did that guy also submit an edit suggestion to your answer?

Loong

I don't think so.

Jan

Random stuff:

io9.gizmodo.com/if-earth-had-a-ring-like-saturn-508750253

orthocresol

I'll read that tomorrow when I wake up :D

Goodnight everybody

Loong

@Jan Did you find that here: physics.stackexchange.com/q/281828/59991 ?

Jan

6:33 PM

@Loong Busted ;)

@orthocresol No need to read, just look at the pretty pictures

How do I say 'the pKa value is typically lower by <something like 1, 2 or 3; i.e. a small single-digit number>'?

Jan

7:13 PM

-1

Q: Identify the name of following compound

Identify the name of this compound: a. bicyclo[2.2.0]octane b. bicyclo[0.2.2]hexane c. bi

homework nomenclature

I feel so evil (see my comment).

Loong

Hm, considering also his other question, he seems to have some technical problems: chemistry.stackexchange.com/posts/59642/revisions

user34388

10:56 PM

Is there any directional ionic bond?

And by "ionic bond" I mean "predominantly ionic bond"

Jan

@user34388 No, unless you count hydrogen bonds.

user34388

11:25 PM

@Jan I see, thanks

Does H2O contain a 3c2e bond?

Jan

@user34388 No. Why should it?

chemistry.stackexchange.com/a/59726/7475 <-- comment thread of the day.

Especially:

@Jan go check it out at wolframalpha.com/input/?i=feet%20of%20mercury. This may explain it to you why theres time in the equation! — user3043098 4 mins ago

user34388

@Jan but its lowest energy orbital is a bonding orbital containing 2 electrons shared by 3 centres...

Jan

@user34388 In molecular orbital descriptions, you will always have orbitals (and thus electron pairs) spanning the entire molecule.

user34388

@Jan exactly

Jan

The difference comes in when you attempt to localise molecular orbitals. It's not until then that you realise you cannot localise the bonds in $\ce{B2H6}$ in a fully 2e2c way.

user34388

11:33 PM

How do you localize mo?

Jan

Linear combinations. (Basically addition)

user34388

wait, linear combinations of molecular orbitals?

Jan

For example, the water MOs. Just so we are on common grounds, please check them out here.

mo2 + mo3 - a little of mo4 approximately equals a sigma bond to the right-hand hydrogen.

mo2 - mo3 + a little of mo4 approximately equals a sigma bond to the left-hand hydrogen.

user34388

wow...

Jan

mo4 + a little of mo2 approximately gives a lone pair on oxygen.

user34388

11:38 PM

never heard of it before

Jan

Each of those contains two electrons and loosely corresponds to a line in the Lewis structure.

(I learnt to draw lines all the time, even for lone pairs. Dots are reserved for radicals.)

Thus, there are only 2e2c bonds.

user34388

I see

Jan

Not the best image for B2H6 but a starting point …

user34388

sure

@Jan How is the energy of an unoccupied orbital defined?

Jan

Homo-3 + Homo-1 are approximately the banana bond around the bottom. It only contains two electrons. Similarly for Homo-1 - Homo-3 and the top banana.

@user34388 You calculate it. (Unsatisfying answer, innit? ;))

Or, you can measure absorption of photons and thereby determine the energy difference between an occupied and an unoccupied orbital experimentally.

user34388

11:46 PM

What does homo2 look like?

Jan

Tbh, dunno ^^'

user34388

@Jan I see

@Jan and if LUMO was involved there would be 2c2e?

Jan

Hmmm, I think you need two LUMOs to turn that 2e3c bond into two 2e2c bonds.