The Periodic Table

Wildcat

08:06

Aromacity?! Again?! :O

Lol. Aromacity. J had a Chinese colleague who always called it this way. :D

pH13

@Wildcat :D

meow

Wildcat

Found an unanswered qc question from Sep 9 and answered it!

@pH13, hello!

skill patrol

Cool

pH13

@Wildcat do you know books about theo chem that are not esp about comp chem?

Wildcat

@pH13, hmmm... Let me think...

@pH13, but what information do you want to see there if not compchem?

pH13

08:12

@Wildcat maybe it's sth like the helgaker ... don't know

Wildcat

Any general physical chemistry textbook is probably about theory, but not about computational chemistry specifically.

@pH13, oh, wait.

pH13

that's really about how wavefunction methods and the underlying math works but not really about it's use or at least the focus doesn't lie on the "real" comp chem part

Wildcat

@pH13, you mean about quantum but not computational chemistry. :D

I got it!

pH13

yeah ... xD

that also lead me to think about, if the szabo ostlund might need to get into that theo chem category

Wildcat

@pH13, I think Szabo & Ostlund nicely fit into quantum chemistry category rather then computational one

they mostly discuss theory and not applications

applications are there just to clarify the theory

pH13

08:15

exactly

and I think it's the same with helgaker's book

Wildcat

Another book which I like is one by Prof. Mayer entitled "Simple Theorems, Proofs, and Derivations in Quantum Chemistry"

pH13

I will write a meta answer on the thread about that

the theo chem category might need to be renamed to theo/quantum chem or only quantum chem

Wildcat

@pH13, well, theoretical chemistry is not limited to quantum chemistry. We have few other theories heavily used, such as, thermodynamics & kinetics, for instance.

pH13

so?

Wildcat

But in this sense theoretical chemistry is a synonym to physical chemistry.

skill patrol

08:19

All chemistry is theoretical until you get into the lab :D

Wildcat

So, we don't need both theoretical chemistry and physical chemistry.

pH13

ok

so quantum chemistry?

Wildcat

well, we have to think carefully indeed do we need to divide quantum & computational chemistry into two separate categories or not

these two usually goes hand-by-hand

pH13

I think, I came up with both to separate the "applied theo chem" == comp chem from the "real" theoretical theo chem

but you are right, maybe this is not necessary

skill patrol

What do you want to learn about?

pH13

08:31

@skillpatrol what do you mean exactly?

skill patrol

22 mins ago, by pH13

@Wildcat do you know books about theo chem that are not esp about comp chem?

pH13

I was just rethinking the current two categories and if books are currently correctly categorized or not

skill patrol

I see.

pH13

and Steven Bachrach's book is one good example for separating the application from the theory

and that leads me to think if there are books that do it the other way around

because most books that I have, do work about both points, the theory and the application to a certain degree without diving into both very deeply

Secret

12:06

so fed up with people thinking chemistry + biology = Drugs and pharmaceuticals

inɒzɘmɒЯ.A.M

@Secret Just organic.

Secret

biology is not just for making drugs, yet a lot of universities and professional societies such as ACS tend to associate them together

inɒzɘmɒЯ.A.M

12:48

@Secret Yeah, but biology ~ 0 without chem. :P

Secret

No I understand that, I mean, they tend to associate biological chemistry fields with pharamaceuticals

So many researches presented in that field tend to focus on how some drug X can supress cancer Y, or diabetes etc.

There's also fluoresence imaging and fluoresent labelling of cells, but most of the researches almost always have a disease as part of their aim

But there's more to biology then just medicine, such as stages of growth, microbiological nutrient cycles, environmental chemistry where biotic factors play a major role in degradation of waste products or other metabolites, geneti…

inɒzɘmɒЯ.A.M

Not interested in biology that much. You might talk to my nerd friend @Berne . . . When he meets the Table.

But I agree Bio can be interesting.

It's big molecules anyway.

pH13

@Secret I tend to some "citation needed" for your they tend to associate biological chemistry fields with pharamaceuticals ... i.e. who is "they"?

inɒzɘmɒЯ.A.M

@pH13 It's them.

pH13

@inɒzɘmɒЯ.A.M ah, them ... then everything is clear

inɒzɘmɒЯ.A.M

12:55

So is there any further questions?

Secret

ok, found a counterexample to my claim:
http://chemistry.harvard.edu/pages/chemical-biology

Some examples (one of them is my uni:
http://www.chemistry.unsw.edu.au/research
http://sydney.edu.au/science/chemistry/research/research-areas.shtml

Note that whenever biology is mentioned, it is focused on the medical side of things

I think there might be more uni examples...

Wildcat

@Secret, yeah, but wait.

Secret

another example
http://www.chem.ox.ac.uk/researchthemes.asp
and counterexample
http://chemistry.mit.edu/research/biological

Wildcat

Who told you that these guys are not doing medicinal chemistry?

I mean

biology is not limited to medicine

right

but what if they indeed do only the medical research?

How should they call it?

Medicinal chemistry, for sure.

For department names, journals categories etc.

Secret

I understand, what I am trying to say is that (at least for the examples up there), the research themes labelled "biological chemistry" are actually more medical oriented if you look into them in detail.

Wildcat

13:05

@Secret, but that is fine, i think.

Bio chem is more general than medicinal.

Secret

which this caused me to become curious, is the medical side of bio chem more popular than other aspects of biochem?

inɒzɘmɒЯ.A.M

Not sure if is popular, but seems to be the most 'popular'.

Argh, I mean the other sense.

Wildcat

@Secret, it is surely the most popular part of bio chem.

inɒzɘmɒЯ.A.M

Like, the normal people's beliefs.

Wildcat

I think for a very simple reason: money talks.

Secret

13:08

gah, conflict of interest at play again...

Wildcat

as always

inɒzɘmɒЯ.A.M

Did anyone say play?

Wildcat

13:23

Did anyone say conflict?

Secret

Thinking tree:
Money talks->Some groups of people unhappy->conflict of interest->mess->and mess->My brain go BSOD

but anyway that's just my opinion

Wildcat

Someone will always be unhappy.

pH13

14:37

@Wildcat are you still there but invisible like ninja cat?

inɒzɘmɒЯ.A.M

I'm still there.

pH13

but you will have no idea on how to answer my question correctly :(

inɒzɘmɒЯ.A.M

Yeah.

pH13

so ... whazzup in tabriz?

inɒzɘmɒЯ.A.M

Tabriz's gas molecules.

No CV to review (╯°□°）╯︵ ┻━┻

9

A: Is 3,5-diethyltoluene an accepted IUPAC name?

Names like toluene are "retained names". In chemistry, a retained name is a name for a chemical compound that is recommended for use by a system of chemical nomenclature (for example, IUPAC nomenclature), but that is not fully systematic. - Wikipedia ‘Retained names’ are traditional or c...

One vote away（ノT＿T)ノ＾┻━┻

:o

Whoever that upvoter was . . . (/¯◡ ‿ ◡)/¯ ~ ┻━┻ (づ｡◕‿‿◕｡)づ (づ｡◕‿‿◕｡)づ

Jan

15:07

Hello everybody and -molecule o/

0

Q: Why is H3PO2 more acidic than H3PO4?

Please explain why $\ce{H3PO2}$ is more acidic than $\ce{H3PO4}$ logically. Please do not provide experimental reasons like $pK_a$.

acid-base

Anybody know why this is the case? It seems very non-trivial to me …

Wildcat

15:31

@pH13, now I'm there! :D

pH13

ninja cat :D

@Jan this might be a possible solution

@Wildcat when excitations are calculated with i.e. tddft

then I get the information about from where to where an electron is excited

do negative coefficients for such an excitation have any meaning?

Jan

@pH13 But that doesn’t really rationalise it imho. An OH group should provide a much better electron withdrawer than a hydrogen, especially since the P-H bond is polarised towards phosphorous.

Wildcat

@pH13, yes.

9

Q: Interpretation of TD-DFT results

For the first time I'm doing TD-DFT calculations (wB97XD functional) in Gaussian 09 for an open-shell system and the results look like the hell of a mess for me. The molecule is rather big, so I started with just 10 excited states to see how it would work. First off, the ground electronic state ...

quantum-chemistry spectroscopy density-functional-theory td-dft

Look who asked it! :O

so

pH13

I read that but don't think, that it helped me :o

Wildcat

oh, yeah

true

there is no example of negative coefficients

pH13

15:35

you have got A -> B and A <- B but both with positive coefficients

I've got only A -> B with positive and negative coefficients

Wildcat

@pH13, generally speaking, that should be fine.

You have a wave function as a linear combination of singly-excited Slater determinants.

pH13

it's not about fine or not fine, just about if it has a meaning like your arrows, or if it is just a solution and only the squared coefficients have a meaning

Wildcat

The coefficients can in principle be even complex numbers/

But they are usually restricted to be reals.

pH13

@Jan hm ... I have to do my tdddft stuff right now x)

Wildcat

Negative coeffs are as good as positive.

pH13

15:38

@Wildcat ok, so it's nothing like positive = "->" and negative "<-"

Loong

@Jan I am not quite convinced that this is actually true. I found contradictory values for the pKa of phosphinic acid.

Wildcat

no, i don't think so

pH13

@Wildcat did you find out more about your de-excitation?

Wildcat

@pH13, no. :( Not enough time to dig deeply.

pH13

@Wildcat that's sad

Wildcat

15:41

I'm learning DFT currently...

TD-DFT is next on the list

The problem with learning DFT on your own is that there are 2 kinds of books:

1) Those that are too "mathy".

2) Others that are completely messy. XD

pH13

true story

but from what I can see, you don't have problems with math :o

Wildcat

@pH13, but I have problems with time. :D

pH13

the day has got 24 hours and if this is not enough, use the night also

Wildcat

Need to understand just the basics but as quickly as possible.

@pH13, no way. Nights are for sleep. :D

pH13

nights are for sleep ... pfff xD

Wildcat

15:45

for hunt also

hunt for humans

=^.^=

pH13

xD

Jan

@Loong Interesting, but Wikipedia seems to state ones, where H3PO2 is lower than H3PO4.

pH13

thx @Wildcat

Wildcat

@pH13, my pleasure.

Loong

@Jan Most sources show lower pKa for H3PO2. However, German Wikipedia refers to research.chem.psu.edu/brpgroup/pKa_compilation.pdf which includes thermodynamic values of 2.23 for H3PO2 and 2.12 for H3PO4.

Jan

16:30

@Loong So what is a thermodynamic pH as opposed to a non-thermodynamic one?

Loong

@Jan I don’t know. But we should make sure that we compare values of the same kind.

Wildcat

The pH scale as shown above is called sometimes "concentration pH scale" as opposed to the "thermodynamic pH scale". The main difference between both scales is that in thermodynamic pH scale one is interested not in H+concentration, but in H+activity. What a person measures in the solution is just activity, not the concentration. Thus it is thermodynamic pH scale that describes real solutions, not the concentration one.

chemwiki.ucdavis.edu/Physical_Chemistry/Acids_and_Bases/…

Go with thermodynamic scale.

Since it is the reality.

Jan

That makes the whole thing even more interesting. Thanks cat =3

Wildcat

In fact, if i remember correctly, pH is defined in terms of the hydrogen ion activity, not its concentration.

p[H] is one which defined in terms concentration

But many still use the same symbol for both.

They, they don't follows STANDARDS! ⋋_⋌

pH13

one does not simply follow standards

Jan

16:44

Who needs standards when you can have randoms?

inɒzɘmɒЯ.A.M

Quick, someone give me a question to answer.

Jan

@inɒzɘmɒЯ.A.M How many milligrams are in my flask?

Loong

@inɒzɘmɒЯ.A.M try this: chemistry.stackexchange.com/q/35330/7951

Wildcat

This guy keeps screamin', he's paranoid. Quick! Someone get his ass another steroid. :D

inɒzɘmɒЯ.A.M

@Jan There are no milligrams in your flask. There's only . . . chemistry . . .

Wildcat

16:51

@inɒzɘmɒЯ.A.M, give the answer in a very easily understandable way!

@inɒzɘmɒЯ.A.M, I'll check that!

inɒzɘmɒЯ.A.M

@Loong What's today's date?

Wildcat

@Jan there is no flask, Neo!

inɒzɘmɒЯ.A.M

@Loong wait for another month please. Answering now won't get me a necromancer.

Wildcat

Don't fret! I'm trying to write (a) canonical answer(s) to this question, will hopefully get it done tomorrow. — inɒzɘmɒЯ.A.M Aug 21 at 20:28

Well, well, well.

tomorrow

hopefully tomorrow

inɒzɘmɒЯ.A.M

I deny. I didn't comment.

(•_•)=ε/̵͇̿̿/'̿'̿ ̿ – =͟͟͞͞ =͟͟͞͞ ﾍ( ´Д`)ﾉ

^ me ^ whoever starred that

Wildcat

16:53

I deny your denial!

inɒzɘmɒЯ.A.M

Better.

@Wildcat I'LL KILL YOUR DENIAL AND HIS FAMILY! (•_•)=ε/̵͇̿̿/'̿'̿ ̿

Wildcat

@inɒzɘmɒЯ.A.M, try to catch it first!

inɒzɘmɒЯ.A.M

Tries to catch it first

pH13

"One does not simply answer tomorrow." starring: @inɒzɘmɒЯ.A.M

inɒzɘmɒЯ.A.M

@Bon you don't wanna come here. There's so many bullets flying around.

@pH13 I could've meant tomorrow in a figurative sense.

pH13

16:57

c'est @bon c'est @bon ♫

Jan

Oh the fun =D

(it's 15.1)

inɒzɘmɒЯ.A.M

@Bon talk or I'll shoot. (•_•)=ε/̵͇̿̿/'̿'̿ ̿

bon

Je sui @bon

inɒzɘmɒЯ.A.M

Try harder.

Jan

You're lacking a letter, @bo.

bon

16:58

@Jan :( I never did french

Jan

That explains it ,)

Wildcat

Tomorrow may refer to:
The future, that which occurs after the present
Tomorrow (time), the day after today

inɒzɘmɒЯ.A.M

It doesn't. Even I know it's Je Cyrus @Wildcat.

Wildcat

Damn, there are two meanings. :|

inɒzɘmɒЯ.A.M

Hah!

In your bullets!

bon

16:59

I learned something new today

21

Q: What is a nerf?

In the classic scene, Princess Leia slams Han Solo by calling him a stuck up, half-witted, scruffy-looking nerf herder While clearly this cuts Han to the bone, I'm curious what this actually means. Presumably it is someone who herds "nerfs" for a living, ...

star-wars terminology

inɒzɘmɒЯ.A.M

So what is a nerf?

Jan

Open the link.

Then start answering your own question.

inɒzɘmɒЯ.A.M

If it isn't something I can eat, I don't care.

Jan

All for the self-learner badge.

inɒzɘmɒЯ.A.M

I won't specially care if it's not a type of ice cream.

Jan

17:00

I think you may be allowed to eat it.

bon

You could eat it

You can also herd it :D

inɒzɘmɒЯ.A.M

Does it taste delicious? I could also eat hydrogen cyanide.

Jan

My Jewish colleague can eat it, so chances are, so can you ^^

inɒzɘmɒЯ.A.M

(╯°□°）╯︵ ┻━┻

I don't like that much hair in my food.

Jan

Well you shouldn't eat it skin and bones D=

inɒzɘmɒЯ.A.M

17:06

In any ways, 23 upvotes for two sentences and a picture is way too much.

Jan

I've answered so many questions where I thought 'how the heck did I get over 10 score on that', that I've stopped questioning it.

pH13

@Jan that's probably the best

bon

The number of upvotes on an answer is largely determined by how many views the question gets, not by how good the answer is. Some of what I consider my best answers only got a couple of upvotes whereas some really quick ones got loads

3

Jan

@bon This one exactly.

inɒzɘmɒЯ.A.M

The only thing I'm happy about is that my top question is a good-quality and well-researched problem, not just something popular.

@bon Furthermore, rep isn't a measure of trust or anything, it just is a crude way of determining how much time you've spent answering/asking. It doesn't even do a good job of demonstrating participation.

Like for example, I have only 3k but I'm close to two steward badges. ᕙ(⇀‸↼‶)ᕗ

Jan

17:14

I don't even have reviewer badges *goes sulking in the corner*

That is, neither here nor on German Y,…,Y

inɒzɘmɒЯ.A.M

0

Q: if ethanol mixed petrol comes in contact with water?.is it converts in water?

We have now 10% ethanol mixed petrol .seller says that if this petrol comes in contact even 10 ml of water ,all ethanol which is mixed in the petrol is convert in to water ,is it true?

inorganic-chemistry

Could someone edit this? The random periods are on my nerves.

.

Jan

.God ,what is it with Indians and inverse punctuation spaces ?I really don't understand it

pH13

@Jan I wanted to write the same

Jan

Beatcha to it ;p

inɒzɘmɒЯ.A.M

@pH13 No ,. but. you? wanted! to writ sth... prolly! better !!!

Haha it feels like a speed bump.

Jan

17:21

I think that question is a waste of editing time. I'm gonna wait for it to appear in the close votes review queue in a few minutes x3

Working towards reviewer.

Jan

17:34

Why does the late answers review queue exist anyway? So new users there get six instead of three eyes?

Loong

@Jan "Late answers tend to be seen by fewer people than answers posted soon after the question was asked, so the review queue helps ensure that these answers meet the same quality standards as all other answers." here

Mithoron

Well, they are often bad...

bon

Which is why the queue exists I guess - so they get deleted

inɒzɘmɒЯ.A.M

ICE CREAM TIME

bon

CHOCOLATE FLAVOUR ICE CREAM

inɒzɘmɒЯ.A.M

17:44

It has some chocolate.

Jan

Where is there ice cream? =D

bon

In my freezer

inɒzɘmɒЯ.A.M

In my hands

Jan

I disagree with the wordings 'first few posts' I found on meta. From what I saw on German.SE, only the first post of a user is put into first posts/late answers queues.

inɒzɘmɒЯ.A.M

The first answer and the question appear in the queue.

Jan

17:46

It would make more sense, if all late answers of a new user be placed into Late answers; say having a threshold of 50 rep.

inɒzɘmɒЯ.A.M

Even if that answer is two months later.

I wonder who reviewed my first post.

O.o I wonder what my first post is.

Jan

Probably a deleted one ;)

inɒzɘmɒЯ.A.M

Hah!

Jan

Actually no, you would see them.

inɒzɘmɒЯ.A.M

Yeah.

Jan

17:48

Usually I only see only an answer or only a question by one new user. But then, I may have not seen any user who does both …

inɒzɘmɒЯ.A.M

N00bie! :p

Jan

Speaking of late answers … that question just sparked my colleague to say: "who asked that? Does he have children? If not, he's a prime candidate for the Darwin award!"

3

Q: Hydrazine synthesis

I'm trying to make rocket fuel by hydrazine and hydrogen peroxide with home products my question is: Is there any way to synthesize hydrazine with bleach and ammonia, using $\ce{H2SO4}$ as a catalyst? I wanna put an action figure in orbit. Thanks in advance!

everyday-chemistry synthesis home-experiment

That being the question.

bon

20:45

To all germans @Martin-マーチン @Jan @pH13. chemistry.stackexchange.com/questions/38046/…

pH13

I guess it's easier to buy a new brush oô

and cheaper

bon

On a side note - is this sort of question on topic. It doesn't really seem to come under any of the categories listed in the help centre

Yeah I don't really know why he's asking the question

pH13

for me it's not

bon

I am inclined to agree

Jan

22:43

I would agree with the off-topicness, too @bon @pH13

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