The Periodic Table

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3:29 AM

@Aesin I tried setting fire to a drop of picric acid before. No effect. But my chem teacher did tell me that it's dangerous during synthesis.

Manishearth

4:10 AM

@Aesin It also makes your fingers yellow--doesn't..get...washed..off.

3 hours later…

Manishearth

6:58 AM

@nhinkle whatcha doing here?

2 hours later…

Aesin

9:10 AM

@Manishearth: Take a look at the structure if you haven't - it's a TNT analogue, so it'll just burn unless you detonate it with shock (or possibly electrical charge). The handy DoD Unconventional Warfare manual lists it as a high explosive bursting charge in crystalline form.

Manishearth

9:37 AM

I know that's a TNT analogue--that's why I figured it was an explosive. I knew about the shock thing, I tried to whack it to provide shock but it didn't work (didn't expect it to)

Me: Oh wow, that yellow stuff in the lab is 2,4,6-trinitrophenol.. Looks like TNT. Ima explode it next time!

(next day)
Me(to prof): Can I explode some picric acid? It looks like TNT.
Prof (knowing smile): Sure, why not?

Me(puts filter paper+picric acid on burner): It's not working! Oh wait..TNT needs shock.

Me (keeps it on burner and whacks it with a test tube): whack whack whack

Me: pours a few drops down the burner

Prof: Ha, none of that will work. You need to detonate it properly. But it's extremely dangerous to synthesize

Me: can I synthesize it?
Prof: No

/me wishes that he had access to nitroglycerin

2 hours later…

Manishearth

11:41 AM

@Fx I've found an answer to your R-S question, but it cites class notes. I'm digging for an IUPAC reference or the original CIP paper

Manishearth

11:53 AM

/answers it anyway

(CIP paper is paywalled)

F'x

@Manishearth ask, and you shall receive: dl.dropbox.com/u/52398724/CIP.pdf

@Manishearth the CIP paper doesn't mention lone pairs

Manishearth

@Fx Hmm... then where did everyone else get that info?

F'x

@Manishearth if I knew, I'd be writing an answer to that pesky question :)

Manishearth

There is this paper onlinelibrary.wiley.com/doi/10.1002/anie.198205671/abstract as well, by the third author. Dunno if it contains anything useful

Found an IUPAC pdf, one sec

F'x

@Manishearth nothing more in there

Manishearth

12:05 PM

I sort of found it in an IUPAC paper

authoritative enough?

THey talk about "phantom atoms"

iupac.org/publications/pac/1976/pdf/4501x0011.pdf

F'x

@Manishearth yes, I saw your comment

it's an official IUPAC recommendation, so it's authoritative

Manishearth

Except for hydrogen, ligancy, if not already four, is made up to
four by adding "phantom atoms" which have atomic number zero
(0) and are thus always last in order of preference.

F'x

works perfectly for me

Manishearth

K, adding

F'x

don't know how you could get any more authoritative than a IUPAC recommendation… they don't do ISO standards in chemistry, do they?

Manishearth

12:07 PM

@Fx Hmm, yeah.. I was thinking of a ref in the original paper/etc

And that was sort of rhetorical :P

done

4 hours later…

Manishearth

3:57 PM

@Fx By the way, how good do you this question would be? It relates to an experience I have recently, but I think it'd be rather vague to ask here

Basically, we have this tennis-racket shaped thingy that zaps mosquitoes. It consists of an inner, charged metallic grid, and two outer, neutral metallic grids. Basically any item that gets between the grids is zapped.

Now, we had to get a new one recently, and it did sometging peculiar: it made a soft sound--as if the wind was passing through it--and gave off this sweet, heady smell

There was no visible electric discharge going on, and it wasn't shorted since it worked fine.

I believe that the smell was ozone, but can't figure how it can be generated--there was a potential difference, but no current

Also, the whooshing sound seemed to come from every point in the grid.

So, my question would be, "what's going on here?"

Manishearth

Now, I feel it is a bad question, since there are loads of unknown stuff (the fault could be elsewhere), and it's vague. What do you think?

nhinkle

4:18 PM

@Manishearth erm, nothing in particular? I haven't had a chance to participate much on this site yet, but I'm hoping for it to succeed and want to help out.

Manishearth

4:33 PM

@nhinkle alrighty! One thing we do need is quality questions. Good questions, anyway. Have any?

nhinkle

@Manishearth nope. If I did, I would've asked 'em ;)

When I do have questions, of course I'll ask.

I think I'll go do some voting and /review'ing though. That's one way I can help without having much content to provide at the moment.

Manishearth

5:06 PM

@nhi makes sense :) Though /review is nearly empty.. If you want, look for bad posts(grammar, formatting) and fix all that user's posts. Eg the user Ashu. Though I think that Fx and I cleared that.

F'x

5:24 PM

@Manishearth I feel it's a bit open ended

would you recognize the smell of ozone? or was it just guessing?

Manishearth

5:38 PM

@fx no, I wouldn't. Smells slightly metallic, slightly sweet, and makes me dizzy

Yeah, open ended.

F'x

@Manishearth well, I think most people will describe smells differently

the one day I “identified” once and for all was working in a small nonventilated copier room for a full night

Manishearth

That too.. I thought it was ozone due to the fact that ozone is formed near electric discharge

F'x

@Manishearth that, or photodecomposition of dioxygen

but I don't believe you have an electric arc (or discharge) in the zap-racket, or do you?

I thought it simply sent current through anything that touched neighboring wires

a bit like you get electrocuted only if you are grounded

unrelated: I'm trying to highlight some good unanswered questions with bounties, please let me know if you think I'm doing it too much or it risks disrupting the site's development

Manishearth

No, you have an arc. Putting a pencil halfway-through leads to arcing. The issue is, I get the smell/whoosh without sparking--just when the button(which places the inner sheet at higher potential) is pressed.

For that matter, you have arcing in any case (unless you push a pencil tip in and make it touch both grids

I don't think that bounties will be a problem.. But I suggest you throttle it (don't do em all at once)

We don't have a main page that's that active, so some extra clutter won't hurt us.

And I suggest you try to keep 2k rep atleast till protems are appointed.

Currently, we have a small enough number of questions, so we can micromanage 'em :)

Aside from bounties, a bumping edit for the neglected ones (less views, less votes) is good. I do that on Physics some times

F'x

6:02 PM

@Manishearth I don't plan on more than two (I'm limited to three anyway)

Manishearth

Oh right :)

Then that's OK by me

I may place some myself later (ill let yours have some time to themselves, though)

Aesin

6:52 PM

Oh Jeez.

I thought I'd answer an easy question and then realised I'd gone on a massive tangent about why ionic bonding is energetically favourable.

Manishearth

@aesin which one?

The octet?

Aesin

@Manishearth: Yep. :/

Manishearth

On Physics.SE, I once wrote an abominably long answer, and when I go to reread the answer, it strikes me that I misinterpreted the question. And then I have to replace all my hard work with a three-paragraph answer :p

Ionic bonding? Whoa, that is tangential :/

Haven't upvoted it yet, but I feel that the question is a good one in spirit, some edits could really make it good. It's a rather commin doubt, especially since students are taught that inner shells hold 2,8,18,32,... electrons

I'll edit it tomorrow or something, got to turn in soon

G'nite folks.
_/falls asleep_

Aesin

7:12 PM

@Manishearth: I agree, it needs an edit (though whether you want to edit it to the 8-electron rule or cover all the shells is up to you, I'm not sure) but it's an importantly common question to have around.

1 hour later…

F'x

8:40 PM

@Aesin I've provided an alternative answer, very light on quantum chem (not explaining the detailed reasoning of the shells) but including many examples: chemistry.stackexchange.com/a/447/30

like you, I think it's such a common question that we need to provide “reference” answers

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