The Periodic Table

CowperKettle

4:00 PM

@DHMO But I need it to stay at level 3

It's subordinate to heading 4.2

DHMO

@CowperKettle what do you want it to become?

make it level 2, and then level 3 again

CowperKettle

@DHMO It worked for it, but all the rest of the level 3 headings did not follow the numbering

DHMO

@CowperKettle then do it again on the rest of the level 3 headings

CowperKettle

What's the point of it all then?

I might as well print it by hand

DHMO

@CowperKettle I thought you can just select all and then shift-tab

pH13 - Yet another Philipp

4:08 PM

@DHMO "Extended Hückel" is no good method today ... better search for some multiconfigurational methods

DHMO

@pH13-YetanotherPhilipp ok

CowperKettle

@DHMO they are dispersed across dozens of pages

DHMO

@CowperKettle then you might as well print it by hand

CowperKettle

Thank you, Microsoft, for automatic numbering

Here it is.

0

Q: Multilevel numbered headings in Word 2007

I have a large document with multilevel numbered headings 4.1.7. Level 3 heading 4.2. Level 3 heading 4.2.1. Level 3 heading I noticed that 4.2. level 3 heading there that really should be level 2 heading. I changed it to level 2 by using the appropriate style. Then the "4.2.1" change...

microsoft-word-2007

9-BBN

4:26 PM

@Loong yes it is :)

The teacher told me I can buy it to sigma aldrich

yield = 95% and 99.97 of purity

That's not so bad

@Hippalectryon comment vas-tu? (how are you?)

Hippalectryon

@9-BBN Ca va et toi ?

9-BBN

Ca va, tu es à l'ENS du coup ?

Hippalectryon

@9-BBN Non à l'X finalement, c'est compliqué >.>

DHMO

4:41 PM

What does "2" mean in $2\delta_u$?

@Hippalectryon

Hippalectryon

@DHMO in what context ?

DHMO

@Hippalectryon molecular electronic configuration

Hippalectryon

I've never seen $\delta_u$ used for that so I'm not sure

DHMO

@Hippalectryon Then what does the "9" in $9\sigma_g$ mean?

orthocresol

second MO of such symmetry

or ninth

or whatever

Hippalectryon

4:42 PM

never seen $\sigma_g$ either :( we didn't use those notations

DHMO

@orthocresol ok, thanks

Hippalectryon

I didn't do any group theory

DHMO

@Hippalectryon you use something like $\mathrm{a_1}$?

Hippalectryon

just $\sigma_1,\sigma_1^*,\pi_1,\dots$

DHMO

I see

Basically, $\sigma_g$ and $\pi_u$ and $\delta_g$ are bonding, while their opposites are anti-bonding, right? @orthocresol

Loong

4:45 PM

@9-BBN very good :-)

orthocresol

For diatomics, yeah.

DHMO

@orthocresol ok, thanks

@orthocresol for 0 electron density, do you mark 0 or mark nothing?

$5\pi_g^0$

orthocresol

$(5\pi_g)^0$

DHMO

but for other numbers you don't need the parentheses?

orthocresol

but you would only do that if you are trying specifically to show

that it is empty

DHMO

4:52 PM

ok, thanks

orthocresol

theoretically, everything should have paentheses

DHMO

well...

roscoe_casita

Good morning.... I've recently learned about oxidation states in class, and something was not clear to me: H_2O_2 has a net oxidation state of 2*+1, and 2*-2 leading to an unbalanced oxidation state correct?. If that is the case... then what are the other possible oxidation states of H/O... and where can I find the oxidation states for the rest of the elements?

DHMO

@roscoe_casita no, each O has -1 oxidation state

H can be -1, 0, or 1

O can be -2, -1, 0, 1, or 2

roscoe_casita

@DHMO interesting. Are these standard tables that can be looked up somewhere?

DHMO

4:55 PM

List of oxidation states of the elements

This is a list of known oxidation states of the chemical elements, excluding nonintegral values. The most common states appear in bold. The table is based on that of Greenwood and Earnshaw, with additions noted. Oxidation state 0, which occurs for all elements, is implied by the column with the symbol of the element. The format of the table, which was devised by Mendeleev in 1889, shows the periodicity of the oxidation states of the elements. == List == A figure with a similar format (shown below) was used by Irving Langmuir in 1919 in one of the early papers about the octet rule. The periodicity...

roscoe_casita

hmmmm alright

@DHMO the project I've been working on is to 'build a better battery... equation generating machine' in software

DHMO

@roscoe_casita I fail to see how the two link together

roscoe_casita

so far it now builds balanced, whole equations.

Given a set of compounds, generate ALL of the reactions

the next step is to filter the reactions to only redox reactions

so given a complete whole reaction (no ions or charges), determine if the reaction is a redox reaction given usage of oxidation state numbers

changing*

DHMO

ok

roscoe_casita

thus, knowing the exact discrete oxidation states that each compound can take on becomes critical, because H 2*+1, and O 2*-2 becomes unbalanced and breaks the machine ^

pH13 - Yet another Philipp

5:02 PM

maybe the machine gets oxidized

roscoe_casita

I try to avoid lookup tables, as they tend to be incomplete...

pH13 - Yet another Philipp

knowledge is incomplete ...

roscoe_casita

given these tables...

H_2O_2 can take on {H:2*+1 and O:2*-1} or {H:2*-1 and O:2*+1} ?

DHMO

@roscoe_casita if I say yes, many people would fight me

but I still say yes.

pH13 - Yet another Philipp

@roscoe_casita next thing to learn is electronegativity

orthocresol

5:06 PM

well, yeah, those tables don't tell you anything

DHMO

@roscoe_casita the oxidation states of the same elements can be different

orthocresol

it could be 0 and 0 for all you know

roscoe_casita

aye

orthocresol

electronegativity is what decides the oxidation states

DHMO

for example, in Na2S2O3:
Na1 = +1
Na2 = +1
S1 = 0
S2 = +4
O1 = -2
O2 = -2
O3 = -2

notice that S1=0 and S2=+4

roscoe_casita

5:06 PM

the element who is more strongly electronegative gets to be in the more preferred
state?

DHMO

@roscoe_casita no, the more electronegative element gets to be in the more negative state

roscoe_casita

@DHMO this is bad news for my program... that is combinatoric
in nature

@DHMO k, so if I was partitioning a compound into a set of oxidation states

then start with the more electronegative elements, and assign them the 'more' negative state

DHMO

oxidation state is kind of my (and everyone here's) second nature...

I don't really know how I derive the oxidation states

roscoe_casita

@DHMO hrmm, understand.

yeah, I'm reading up on the fractional oxidation states... what exactly is oxidation state?

DHMO

> "Oxidation state" is defined as the charge an atom might be imagined to have when electrons are counted according to an agreed-upon set of rules:

1. the oxidation state of a free element (uncombined element) is zero
2. for a simple (monatomic) ion, the oxidation state is equal to the net charge on the ion
3. hydrogen has an oxidation state of +1 and oxygen has an oxidation state of −2 when they are present in most compounds. Exceptions to this are that hydrogen has an oxidation state of −1 in hydrides of active metals, e.g. LiH, and oxygen has an oxidation state of −1 in peroxides, e.g. …

roscoe_casita

5:12 PM

well... there isn't a lot of combinations

easy enough to enumerate all possible combinations of all atoms in a compound, and find the set that works correctly

DHMO

@roscoe_casita see how that works with OF2

roscoe_casita

yeah, F is -1, O +2

DHMO

nice

HOCl?

roscoe_casita

Cl -1, H -1, O +2 ?

DHMO

@roscoe_casita nope

roscoe_casita

5:14 PM

hmmm, I don't like that because O is more electronegative

Cl : +1, H +1, O -2

DHMO

brilliant

KMnO4

@orthocresol is it better now?

1

A: What is Bimolybdenum's hybridisation?

You probably meant dimolybdenum. Its electronic configuration is given in Dimolybdenum: nature of the sextuple bond, Bruce E. Bursten, F. Albert Cotton, Michael B. Hall, J. Am. Chem. Soc., 1980, 102 (20), pp 6348–6349: $$\ldots\mathrm{ 9\sigma_g^{1.88} 5\pi_u^{3.78} 2\delta_g^{3.42} 10\sigma...

roscoe_casita

O: -2, K: +1, mn, +7

DHMO

@roscoe_casita nice

CH2Cl2

9-BBN

@Hippalectryon te plains pas tu n'es pas dans la plus mauvaise école.. vous faites de la chimie à l'X ? Non vraiment ? :P

roscoe_casita

Cl: -1, H+1, C: 0

9-BBN

5:16 PM

@Loong thank you

DHMO

nice

roscoe_casita

damn

yeah, enumeration is going to be the quick way

DHMO

what is enumeration?

9-BBN

[Na(2,2,2-crypt)]Na ?

roscoe_casita

so say you wanted to 'calc' what the oxidation states where of CH2CL2

9-BBN

5:17 PM

What about Na :P

roscoe_casita

you have a list of oxidation states for C, H, Cl

so you try assigning C to one of them H to another, Cl to another

check if it balances to 0

then try changing one state, check again

so its {elemental oxidation states}*{elements}*{number of elements in compound}

exponential in nature

DHMO

@roscoe_casita maybe I tell you how I derive

roscoe_casita

aye, that would be a good heuristic

DHMO

I derive by mentally picturing the structure (which I don't know how your program can do)

because enumeration would fail for large compounds like CH3CH=CHCOOH

roscoe_casita

I think you're correct

go on

DHMO

5:21 PM

@roscoe_casita i finished my speech

9-BBN

@roscoe_casita you can also check with the electronegativity of each atoms

For example with NaH chi(Na) < chi (H) then Na+ with H-

roscoe_casita

hmmm actually its pretty small

CH3CH=CHCOOH ~= (4*9)*(4*3)*(2*5)

~4320 combinations of oxidation states,

one is right, pick that one,

DHMO

how do you know which one is right?

roscoe_casita

check them all.

100,000 reactions/ 1 second currently,

DHMO

check them all for what?

what is the criteria?

roscoe_casita

5:25 PM

that the oxidation states internal to a compound sum to zero

9-BBN

only that ?

roscoe_casita

aye, but now you have an assignment of oxidation states to atoms

you can do that for all compounds ones, then store the results

then in a given reaction, look up the assignment of oxidation states, and determine if the reaction is a redox

this is great, thank you all =)

9-BBN

What about carbone monoxide ?

roscoe_casita

5 possible zero assignments ;)

9-BBN

Does your prgm give the good answer?

pH13 - Yet another Philipp

5:27 PM

@roscoe_casita and what would be the best then?

roscoe_casita

that is a question i don't know how to answer

so of the possible 5 assignments what would be the correct one?

9-BBN

Then one who respect at least the quantum chemistry

:P

roscoe_casita

lol, aye, but I'm not at that level yet

this is to eliminate computing things that don't need to be computed ;)

So there are 5 assignments to the pair of (C,O) in CO: [ (0,0), (-1,+1), (-2,+2), (+1,-1), (+2,-2)] which would be the 'correct' assignment of oxidation states?

I assume O would default to -2, and C to +2

but why?

9-BBN

Remove +2 for the oxygen lol

roscoe_casita

and can we just use the list of electronegativities to assign from this set of possible states?

Rubisco

5:31 PM

Because we tell them to.

DHMO

@9-BBN quoi?

roscoe_casita

why @9-BBN ?

DHMO

oxygene est +2 en OF2

9-BBN

If you have CO

roscoe_casita

there are some 60k + compounds in the database

think in general, the assignment is possible just not logical

but the electronegative rules would determine that

alright

9-BBN

5:33 PM

You can also do something else

roscoe_casita

such as?

9-BBN

Check with the electronegativity and make a list from the most probable (which one respect the electronegativity) to the less at first time

roscoe_casita

alright @9-BBN I'll keep thinking on this (this is a years long project by the way... here is some picture of the current state)

9-BBN

But if you have CO I guess you'll have troubles without quantum chemistry

DHMO

@9-BBN classically it is explained by 2 double bonds plus 1 dative bond

roscoe_casita

5:36 PM

with electronegativity as the assignment prioritizer, it is possible to extract a single 'correct' value from the list of possible assignments.

DHMO

or if you prefer to use formal charges, -C=O+

roscoe_casita

alright, keep it easy all.

thanks you for the help!

DHMO

@roscoe_casita what the hell are those (non-)compounds?

9-BBN

@DHMO i do not like your representation

Rubisco

@roscoe_casita Are you supposed to untie this knot or something?

I'm not gonna help with that.

DHMO

5:37 PM

@9-BBN I didn't advocate for that representation; I'm just saying how it would be represented classically

Rubisco

@9-BBN I do not like your lack of capitalization

9-BBN

And there is a triple bonds between C and O

@Rubisco capitalization ?

DHMO

@9-BBN Yes, I meant -C#O+

Rubisco

@9-BBN 'i' -> 'I'

roscoe_casita

@DHMO they came from this database: materialsproject.org

9-BBN

5:39 PM

In France we right no capital letters in sentences expect at the begining

roscoe_casita

@Rubisco this is a small view of the hypergraph / reaction network of all possible reactions for the given set of compounds

DHMO

@roscoe_casita I have never seen anything resembling H24O12

roscoe_casita

I think they represented H2O that way,

I don't know why

9-BBN

@roscoe_casita you can also check octet rules for elements before Neon

DHMO

alright

9-BBN

5:41 PM

And duet for hydrogen and helium

roscoe_casita

thanks again, back later ;)

DHMO

@9-BBN duplet, because English

9-BBN

duplet

Rubisco

I like duet better

9-BBN

French is better sure

Rubisco

5:43 PM

German is betterer

I'm definitely not saying that to get more votes.

Definitely.

9-BBN

Anataha Rubisco san desuka? :P

Japanese quite good too

@roscoe_casita periodni.com/oxidation_numbers_calculator.php

orthocresol

Anata wa.

I mean, I know you write/type it with ha

9-BBN

We pronounce "wa" but we write "ha"

When you say "watashiha" the "ha" is pronounce "wa"

orthocresol

I know.

But when you are writing it out in romaji it should be wa.

9-BBN

Oh OK ^^

orthocresol

5:49 PM

I've always seen it that way, at least.

9-BBN

I never have written in romaji

Rubisco

@9-BBN No swearing in this chat

Oh God. Somebody save me from Japanese geeks.

They're even worse than Japanese geeks.

9-BBN

@Rubisco do not refer to religion in this chat thank you

Yeah I've ever been modo :P

Rubisco

Flags itself as abusive

9-BBN

LOL

I forgot to say please

@roscoe_casita The oxidation number of a free element is always 0.
The oxidation number of a monatomic ion equals the charge of the ion.
Fluorine in compounds is always assigned an oxidation number of -1.
The alkali metals (group I) always have an oxidation number of +1.
The alkaline earth metals (group II) are always assigned an oxidation number of +2.
Oxygen almost always has an oxidation number of -2, except in H2O2 (when it is -1) and in OF2 (when it is +2).
Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.

I don't know if all the statements are true everytime

IfChemDraw do it, hack it :P

DHMO

5:54 PM

Wrong statements:
The alkali metals (group I) always have an oxidation number
The alkaline earth metals (group II) are always assigned an oxidation number of +2.
Oxygen almost always has an oxidation number of -2, except in H2O2 (when it is -1) and in OF2 (when it is +2).
Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.

Rubisco

@DHMO And these are wrong, why?

9-BBN

Then @DHMO will give you exhaustively all cases in which this is false

DHMO

1. alkalides
2. https://en.wikipedia.org/wiki/Low_valent_magnesium_compounds
3. − 1⁄2 (superoxides), − 1⁄3 (ozonides), 0 (elemental, hypofluorous acid), + 1⁄2 (dioxygenyl), +1 (dioxygen difluoride), and +2 (oxygen difluoride).
4. NaBH4

@9-BBN why am I so predictable

Rubisco

@9-BBN That's boring.

Exhaustively boring.

@DHMO Good luck ever finding alkalides.

DHMO

@Rubisco It has been produced

9-BBN

5:57 PM

With informatic everything is fast but if some of these statements are true it will be faster sure

Rubisco

@DHMO Have you?

DHMO

@9-BBN superoxides are not uncommon

@Rubisco Have I what?

Rubisco

DHMO, the point is, it's fun showing off inaccuracies, but what you, I, and everyone else is studying is an approximation of reality, so after a certain degree, it becomes meaningless.

@DHMO Seen, or produced alkalides.

DHMO

@Rubisco superoxides are not uncommon

Loong

Aug 23 '15 at 21:18, by inɒzɘmɒЯ.A.M

I'm writing an epic answer about oxidation states. The curious may see my progress here.

Rubisco

5:59 PM

@Loong IKR . . . Kids these days

DHMO

Aug 23 '15 at 21:19, by inɒzɘmɒЯ.A.M

Holy moly indeed; I've written 149 paragraphs?!

Loong

in g-block elements, Sep 28 '15 at 11:25, by Loong

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

DHMO

@Loong what is the question?

@Rubisco No, I have not.

Loong

@DHMO "What is Oxidation Number?"

chemistry.stackexchange.com/q/35330/7951

DHMO

@Loong deleted

Loong

6:01 PM

yes, deleted by Community♦

pH13 - Yet another Philipp

@Loong I waited desperately for this answer ...

Rubisco

@Loong I think I still have that answer somewhere, but I saw there wasn't a hype at the time to write canonical posts, and MS word kept messing with SE's editor. I'm ready to finish it whenever we start writing some canonical posts in an organized manner.

Loong

@pH13-YetanotherPhilipp I still do. ;-)

pH13 - Yet another Philipp

@Loong whatever "zu Recht" would translate to ...

Rubisco

@Loong HEY

@pH13-YetanotherPhilipp Justifiably

But that doesn't make sense.

Or maybe it doesn't make sense at this time of the day

pH13 - Yet another Philipp

6:06 PM

maybe with great justice

@DHMO are those orbital pictures in your answer for free use?

DHMO

@pH13-YetanotherPhilipp no idea

pH13 - Yet another Philipp

then I’d say you better find out

DHMO

@pH13-YetanotherPhilipp if not, should I just use the original link instead?

pH13 - Yet another Philipp

you should find some 4d orbitals with an appropriate license if not

DHMO

@pH13-YetanotherPhilipp the thing is, they're hard to find

orthocresol

6:29 PM

@Rubisco I guess what I did a couple of weeks back was kind of a trial.

These things seem to be well-received and two of them also received alternative answers

Which is a good thing

Rubisco

@orthocresol What did you do?

Everyone, what did he do?

ಠ_ಠ

orthocresol

I suspended your account.

Rubisco

Oh my God. Then I'm a ghost.

I can prolly pass through . . . ouch.

orthocresol

Or, to be precise, that is the first thing I will do at 9 p.m. on Tuesday.

Rubisco

Phew.

I have a few days before becoming hollow.

Until then, I can keep catalyzing things happily.

Loong

6:34 PM

hmm

Rubisco

@Loong NO!1! VOTE FOR ME! THIS IS LIFE AND DEATH NOW

9-BBN

6:47 PM

youtube.com/watch?v=qO8yfBLNVjU the second movement is known and so good to here after the first one sure !

Rubisco

What

pH13 - Yet another Philipp

9-BBN

Listen and shut up :P

Beethoven wants respect

Rubisco

@pH13-YetanotherPhilipp Nom nom

pH13 - Yet another Philipp

@DHMO If I was not doing something wrong, this should be 4d orbitals.

9-BBN

6:51 PM

I have something to confess

pH13 - Yet another Philipp

of hydrogen ... of course

Rubisco

@9-BBN That you didn't vote for me? Gets ready to kickmute

9-BBN

I began to watch Breaking Bad yesterday

Rubisco

Yep, I should kick him.

9-BBN

Is there a limit to the size of a pseudo?

Rubisco

6:54 PM

P-what?

Loong

@9-BBN I think, it's 30.

9-BBN

Well when I worked at GIVAUDAN when I had to make samples for an order, it was possible from the software to create the software to ask at the maxium 5000 samples. We cannot use any engin to help us. So 5000 samples doesn't make sense for that. So here I'm asking for the num of a pseudo. If I put 5000 caraters if you "@" me it will flood the chat lol

I'm evil

to create the order*

orthocresol

Hi Josh, and welcome to Chemistry Stack Exchange! On homework questions, we usually prefer to give a hint rather than a direct solution… — F'x Oct 25 '12 at 7:27

Loong

@orthocresol I saw that.

orthocresol

Times have changed..

Loong

7:06 PM

flagged – this comment belongs on math.stackexchange

Rubisco

7:50 PM

@Loong If I were a mod, I would've migrated it without second thought.

Vote for me.

orthocresol