The Periodic Table

Jan

12:00 AM

=D

(づ｡◕‿‿◕｡)づ

12 seconds before midnight. What a close vote xD

Mithoron

@Jan Don't need to thank me ;)

Jan

I wouldn’t even know who to thank but I feel like giving you chocolate anyway ;)

Mithoron

@Jan You're really into these badges and rep aren't you :D

Jan

They’re magical unicorn points! Which means they’re magic! And they have unicorns! They’re probably pink and sparkly. How could you not like them? *___*

One of my favourite drinks:

Mithoron

@Jan :p

So you're embracing child within you? :D

Jan

12:11 AM

I’m living the child within me to its fullest.

user228700

Hi, everyone :-) I've a quick question about hyperconjugation again. This is what my textbook says:

Jan

And my colleagues have already burst out laughing and confirmed that they will have a lot of fun crafting a hat for my defence

user228700

> "*There is some ionic character b/w the C-H bond"

ringo

Wait... do a lot of institutions do that @Jan??

user228700

> "*Carbon-Carbon double bond acquires some single bond character"

Jan

12:13 AM

@ringo Practically every place in Germany.

user228700

Does anybody know what that means?

ringo

Wow! My group does that too

Jan

@Kaumudi you can represent this in Lewis structure resonance terms: $$\ce{H-C-C=C <-> H^+ C=C-C^-}$$

!!greet/Jan

Chemobot

Welcome to The Periodic Table Jan! Here are our chat guidelines and it's recommended that you read them. If you want to turn Mathjax on, follow the instructions in this answer. Happy chatting!

Jan

(For ChatJax reference)

ringo

12:15 AM

@Kaumudi every bond can be thought of as being some % ionic... essentially, how close are the atoms to their unbonded radii

And it is never 100%

user228700

Riight...

ringo

So all bonds have ionic character

user228700

But how come the carbon-carbon double bond acquires single bond character? Isn't it switching from a single to a double bond?

Jan

Partial single bond character.

ringo

I'm not really sure what it means by that

Jan

12:18 AM

i.e. they’re only 90 % or maybe 85 % double bonds; 15 % single bonds.

Look at my resonance structure above.

user228700

@Jan Ah. Okay. The word 'partial" is important here! Can't blame my textbook-the poor thing has always sucked.

user228700

Alright, thanks guys :-)

user228700

@ringo: Thanks for answering my question about the inductive effect :-) I haven't found the time to visit all those links, but since the bounty ends today, I will do it sometime today and decide what to do. Sorry to have kept u waiting without accepting your answer (which I haven't fully wrapped my head around yet). I was hoping that some others may also answer, but nope :-/

Jan

@Kaumudi I kept @Loong waiting for … how long was it?

user228700

Hm?

Jan

12:22 AM

Also, it’s my philosophy with bounties to always wait until they enter grace period to maximise their advertising effect ;)

user228700

I see :-P

ringo

@Kaumudi perhaps I can improve it

Jan

10 months xD

ringo

Which part is hard to grasp?

user228700

Like I mentioned in the comments, this one:

user228700

12:25 AM

> "Linear free-energy relationships are a quantifiable way of measuring a reaction's sensitivity with respect to a certain parameter."

user228700

From there, I don't understand how these Linear free-energy relationships have anything to do with my 2nd question. In fact, what is my second question? There was only one .__.

user228700

@Jan You kept Loong waiting for 10 months before u accepted his/her answer?! That's rough :-P

Jan

I simply forgot .__.'

Loong reminded me in chat.

Four days ago. I quickly accepted because oops.

ringo

@Kaumudi Linear free energy relationships are how we measure things like inductive effects, for which the standard of comparison is a hydrogen atom

Loong

@Jan You know, anything that shall "Hand und Fuß haben" takes 9 months.

user228700

12:30 AM

I see. Well, alright, I think I'll go ahead and accept ur answer, then. I've only just graduated high school and that's why I wasn't able to make sense of what "Linear free energy relationships" are, but the first part of ur answer makes a lot of sense.

user228700

Although...

Jan

@Loong I thought they say ‘Our loving God punishes minor sins immediately. Major sins are punished after nine months.’ ;)

user228700

The 2nd part of ur answer is a little contradictory to the 1st. In the first part, you thoroughly impressed upon me that it doesn't even make sense to bring the inductive effect into the picture in case of a molecule like $Cl_2$ but in the 2nd part, u said this:

user228700

> "Similar as to what you said, substituent groups will always have the same relative inductive effects no matter the molecule."

user228700

OK, hang on, I think I know how to make sense of what u were trying to say. Here:

user228700

12:36 AM

user228700

In the above ^ compound, the mesomeric effect outweighs the inductive effect in the case of the $COO^-Na^+$ group. Although it is a $-I$ group w.r.t hydrogen, in this case, it is giving, not taking. So does it make sense to say that it's a $+I$ group in this molecule or is it that it's still exhibiting the $-I$ effect but that other effects outweigh this?

user228700

@ringo: Even after having read ur answer, I still dunno what's happening in the case of the above compound.

Jan

@Kaumudi It’s not giving.

COONa isn’t giving. It’s just pulling less strongly.

ringo

The nitro group is highly electron withdrawing

user228700

@Jan The dipole moment is directed in the other direction 'cause as ringo just said, the nitro group is highly withdrawing...but it's still pulling? Really?!

Jan

12:43 AM

Yes.

ringo

It's like tug of war

Jan

The best indicator are the 1H-NMR shifts. The protons next to carboxylate have 8.2 ppm, those next to nitro have 8.3 ppm.

user228700

So if I were asked a question "What is the type of inductive effect exhibited by so-and-so group in so-and-so compound?", I don't even need to check which compound it is to say if the group is exhibiting -I or +I? I only need to know what the group in question does when connected to hydrogen?

Jan

I thought it’s the other way; you replace a hydrogen in a specific compound with whichever group you want to measure and then measure the difference.

user228700

Oh, what? .____.

ringo

12:47 AM

Yes, it is relative to hydrogen

user228700

@Jan I don't understand .__.

ringo

it's $\sigma_\ce{X} = \log \frac{K_\ce{X}}{K_\ce{H}}$

user228700

Stupid inductive effect. Haven't been able to say "Yep, I understand that thing super well" in weeks.

Jan

(By the way, neutral benzene has 7.37 ppm for its hydrogens in DMSO, so there’s some serious pulling going on.)

Actually, I don’t think it matters whether you measure by my definition (replacing hydrogen in a compound with X) or your definition (bonding a compound to hydrogen and seeing what happens). The end result should be mathematically identical.

user228700

$K_X$ and $K_H$ being..?

user228700

12:52 AM

See this is why I posted the effing question! So I'd be able to get loads of answers that may or may not agree with each other.

user228700

If I had more reputation, I'd have placed a larger bounty -___-

ringo

$K$ (upper case) is an equilibrium constant

$k$ (lower case) is a rate constant

@Kaumudi

user228700

Right.

ringo

So it measure how much more/less the species dissociates with the given substituent relative to hydrogen

A different equilibrium forms

user228700

:-/ OK.

user228700

1:13 AM

@Jan: $D_{2v}$?

Jan

Damnit, it’s h, isn’t it?

user228700

Dude, Idk what that is .__.

Jan

I would love to say: see ortho’s group theory tables on meta xD

You know what C_2v is, though, do you?

user228700

Nope.

Jan

Oh, okay …

9

Q: What are point groups and the benefits of using them?

I have heard vague information about point groups and symmetry before but I am unsure how they actually help me predicting physical properties of molecules. How do I assign point groups and what good does it do me? Please answer at a low level.

group-theory

user228700

1:18 AM

Are high school graduates supposed to know what that is?

user228700

From ur question/answer, I guess not :-P

user228700

Thanks for answering my question BTW :-) FINALLY, at least 2 answers!

Jan

But that’s okay. It’s just that once you learnt about them and understood them, the beauty of using them becomes apparant and you’ll never want to stop.

user228700

I see :-)

Jan

Unfortunately, I understood practically nothing about point groups in the group theory lecture (held by Professor Ebert, our most maths-y professor whom we loving called ‘the last unicorn’ because of a bump on his forehead). I then went on to understand point groups from fragments that Professor Klüfers (who I cite really often here) dropped into his inorganic lectures.

How does redacting spammy posts save space @Loong? Or is it related to the content always being visible for diamonds?

Loong

1:34 AM

@Jan yes, exactly. Hence, troll threads can become very large and also slow to work with.

orthocresol

3:16 AM

@Loong What got redacted? I can't see anything.

user228700

5:24 AM

Nvm :-)

Ramanujan

9:13 AM

Hi chat

Is phenyl used in cleaning is same as c6h5

?

orthocresol

-2

Q: Is it 'Phenyl' or 'Phenol' that is used as a cleaning agent?

I often see Phenyl written on cleaning agents in stores. Here are some examples: One day, a guy standing beside me at a store picked up a bottle of phenyl/phenol and he said, "The big corporation got it wrong. It's phenol, not phenyl." I looked up the definition of Phenol, and it reads: ...

everyday-chemistry

Martin - マーチン

9:30 AM

@orthocresol when a post get's deleted as spam/rude (and locked) for the lucky user it'll show up as a single line. for us poor mods, we see the full content, so expecially for long spammy posts and or with narsty, narsty pictures, it should be edited out.

1,3-feeds

10:16 AM

0

Q: The Giant List of Duplicates

For those who haven't been frequenting meta, this post has been suggested numerous times. The intention is to collect together good questions with good answers which can be used as duplicates. While this is obviously a mammoth task, there is no stipulation that it is (or ever will be) exhaustive....

discussion big-list

Secret

10:30 AM

Is there exists a chemical reaction that exhibits endothermic chemiluminescence?

I know that chemluminescence requires the energy released from the chemical reaction to promote the molecule to some excited state which then relaxes via fluorescence or phosphorescence back to the ground state, emittign light in the process

However

I am not sure whether it is thermodynamically favourable to take in some heat from the environment to kick start the excitation process, thus fullfilling the requirement of endothermic reaction

Jan

1:52 PM

I wonder if that type of nasty picture shouldn't be given an additional 'mod flag' so SE staff can permanently remove it from Stack's imgur … but I should really stop caring about the mod- and dev-sided backend ;)

Hit 0.2 krep again. Wow =O

Loong

@Jan I asked a CM. They do not follow what is stored on imgur if it is not linked from a stackexchange site.

Jan

So space on imgur is infinite?

Loong

30

A: Potential to abuse Imgur?

1. Is this behavior expected? Expected as in "You should do this" – obviously not. Expected as in "we know it's possible" – yes. 2. Does it not matter to Stack Exchange and Imgur? It's pretty much impossible to prevent this 100%, at least up front. However, hijacking our Imgur account...

Jan

Please note that: 1) The perceived seriosity of a question is indirectly proportional to the number of exclamation marks. 2) The perceived seriosity is also indirectly proportional to the average font size; and 3) it is equally indirectly proportional to the fraction of bolded text. — Jan 44 secs ago

Loong

2:13 PM

@Jan "cycloheptadienyl cation"?

Jan

Maybe I should go right back to bed … make that trienyl.

Here's a helpful link if somebody does not use punctuation: skillsyouneed.com/write/punctuation1.html

hBy2Py

Heyo, @penta

pentavalentcarbon

Good morning.

You're in CST, right?

hBy2Py

Nope, Eastern

EST spans most of Indiana, all the way through Maine.

pentavalentcarbon

Hmmm, I'm very bad with time zones. Well, I know where it goes on the other end...

hBy2Py

2:20 PM

There's been chatter about parts of New England hopping from Eastern to Atlantic time (1 hr earlier). Personally, not being a morning person, I'd be all for it.

pentavalentcarbon

Of course, there's that little bit of Indiana that's 30 minutes between.

hBy2Py

Full night at 4:30pm in December ... was depressing.

@pentavalentcarbon I don't think it's like that any more.

IN used to be a county-by-county timezone mess

pentavalentcarbon

Oh? This I never knew.

hBy2Py

But now it's all Eastern, except for the NW and SW corners near Gary and Evansville.

Image from here: timeanddate.com/time/us/indiana-time.html

pentavalentcarbon

2008 so it's been quite a while then.

Jan

2:22 PM

@hBy2Py This still makes it a county-by-county timezone mess imho.

pentavalentcarbon

Well, Indiana is kind of a mess anyway...

hBy2Py

@Jan True, but at least there are only two regions, each of which is contiguous.

Before, it was an insane patchwork

Quoting that link:

Time in Indiana has been debated since the Standard Time Act put the state on Central Time in 1918. In 1961, the Interstate Commerce Commission divided the state in Eastern and Central Time, but the new time zone line was not consistently observed. Through the 1960s and 1970s, the counties varied their time zones. A few counties even switched time zones from the late 1970s onwards.
On January 18, 2006, the United States Department of Transportation announced a final rule that would allow 8 of 17 Indiana counties to move to the Central Time. The counties Starke, Pulaski, Daviess, Dubois, Kno…

pentavalentcarbon

Imagine having your TZ change 3 times in 2 years?

Jan

Sounds like Russia.

I wonder if a historical map exists, too …

Coming from the "well-organised" place that calls itself Europe, I never understand why time zones don't follow state boundaries strictly …

pentavalentcarbon

bostonglobe.com/business/2016/08/11/…

hBy2Py

2:27 PM

Couldn't find the legend for it, but:

pentavalentcarbon

Yuck, there's part of Warren where you drive East and go ahead in time.

And one or two others.

Just another excuse for me to mock the Midwest booooooooooooooooooo

hBy2Py

@pentavalentcarbon We're boring and can't lay out our time zones neatly!

Jan

@pentavalentcarbon You know, there are places in the world where you can drive West to go ahead two hours. And I can probably find one where you drive West and go ahead three hours.

pentavalentcarbon

Other places in the world? Inconsequential to me.

2

Jan

Oooh, you can even go West and advance by 3.5 hours.

hBy2Py

2:37 PM

@Jan Clearly, having the world's political boundaries drawn according to such trivial things as natural topographical and geological features was a tremendous mistake. It's time to orthogonalize things, dammit!

Jan

@hBy2Py Oh, Europe is not half as absurd as other places ;)

hBy2Py

@Jan "The straight-line path goes over an 8,000-foot high mountain range? So what?! Climb it!"

paracresol

2:57 PM

@hBy2Py @penta o/

pentavalentcarbon

who doth ping loudly?!

paracresol

'Tis I, who hath pinged thee, lord @penta !

pentavalentcarbon

I ain't no lord and stop pinging me!

paracresol

Okay @penta ._.

@Cowper Hallo comrade! o/

CowperKettle

\o

I'm busy translating

paracresol

3:08 PM

I thought you were done with the Cossack song? ._.

CowperKettle

> Whoever translates a lot, he is quick to sleep; whoever sleeps long, does not sin; whoever does not sin, enters Heaven!

paracresol

...

CowperKettle

@paracresol I'm translating about bioreactors

paracresol

^ Ah!

Why exactly do you you do it anyways?

CowperKettle

To get paid

paracresol

3:09 PM

:D

(0:

Part-timer?

no

O_o

3:36 PM

@paracresol My mom translated for her job for some 30yrs

Jan

Thirty years translating a single document? =O Must have been complicated.

paracresol

3:57 PM

@hBy2Py Ooh, what language(s)?

@Jan Certainly not as complicated as your "thesis" ;)

Loong

4:10 PM

@paracresol why the scare quotes?

Jan

Maybe @paracresol is scared of my thesis?

Jan

4:27 PM

Thinking about it, I don't know how I missed the @paranoia pun there …

paracresol

4:57 PM

@Jan Damn! I thought you'd give it a complete miss X'D

@Loong Well it is one heck of a thesis ;P

18 hours ago, by Jan

@gannex I’m willing to bet my thesis on it.

23 hours ago, by Jan

@paracresol A singer whose voice and songs filled my head while writing my thesis. Pretty much the entire thesis.

Nov 21 at 0:54, by Jan

Why, oh why did I choose to include a word of Hebrew in my thesis?

Nov 20 at 3:02, by getafix

haha, thesis keeping you busy?

Nov 11 at 1:14, by Jan

I was just thinking of linking my thesis as soon as it’s accepted and everything … until I realised that only the g-block elements will be able to read it. And Aaron in a few years’ time.

^ @Jan That one flattered me :3

Nov 8 at 10:44, by Aaron Abraham

@Martin-マーチン The last time I did, he said he wasn't done writing/typing out his thesis ._.

Nov 2 at 18:23, by Jan

@pentavalentcarbon Ah yes, my problem indeed. Sitting on SE rather than working on my thesis ^^'

Nov 2 at 2:43, by Jan

Right, after having answered a few SE questions, let’s go back to organising references into BibTeX format for my thesis …

Jan

You could just have linked the search result …

paracresol

There're a bunch of other "theses" there...I'm just highlighting reference to yours @Jan :3

Jan

Less than a million seconds left to Winterbash =D

hBy2Py

@paracresol Some French, a bunch of Russian.

Alan Watch

5:13 PM

just for once I want to inhale N2O

and want to see how long I will laugh and why I will laugh

Jan

In Germany, you can legally buy N2O-loaded cream whipper capsules. Let the gas into a balloon and breathe in -> done.

paracresol

N2O doesn't make you laugh (outright) ._.

Alan Watch

I thought N2O is legal everywhere

paracresol

Sure, it's an anaethetic and it kinda induces euphoria...but nothing more

Alan Watch

@paracresol it does

paracresol

5:17 PM

O_o

Jan

I'm not sure, I just know it's legal here because a guy from school told me about inhaling it back in the day.

2

paracresol

DAMMIT @JAN!

Alan Watch

I also want to inhale SF6. It makes speed of sound through your throat much slower

paracresol

This is the state of the Vaterland today... sighs

Alan Watch

who has ever tasted D2O?

paracresol

5:20 PM

It tastes...just like water .-.

There's a teeny-tiny bit of D20 in the water you drink o_o

Alan Watch

I meant pure..it hardly affects

Jan

I have a bottle of D2O on the bench but I'm not curious enough to taste.

paracresol

Drinking pure D20 isn't a problem either...unless you make D20 your daily sustenance ;P

Kinetic Isotopic effect ._.

@Jan Go on! Give it a try ;)

Alan Watch

wish if there was an Earth size planet with oceans only of T2O

how much radiations would that planet emit?

Jan

About 57 arbitrary units.

Alan Watch

5:33 PM

can't find on internet which is the most radioactive planet ever discovered

but I guess no planet can beat xray radiation of pulsars

CowperKettle

> Mammals (for example, rats) given heavy water to drink die after a week, at a time when their body water approaches about 50% deuteration.

> "Whoever drinks heavy water, he is slow to die; whoever dies slow, can sin; whoever can sin, will sin! Thus, let us drink beer!"

See, Luther was against drinking heavy water.

Jan

I love how you're inventing a new Luther quote every two hours =D

Alan Watch

save water drink beer quote I see very often..isn't beer contains 90% water itself?

CowperKettle

5:53 PM

@Jan Well, whoever jokes about Luther he is quick to gain stars in chat; whoever gains stars in chat, does not sin; etc.

4

(0:

Transcript for