Sciencemadness Discussion Board - Hate this stuff

Hate this stuff

GreenD - 7-2-2012 at 07:42

Phosgene
Chloroplast / phyll
Ammonium hydroxide (see other thread)
Chrome alum

Why do they do this?!

Pulverulescent - 7-2-2012 at 07:53

(er) What? (

)

P

turd - 7-2-2012 at 08:05

ITHM that phosgene does not contain phosphorus, chlorophyll no chlorine, chrome alum no aluminium, urine no uranium, et cetera, et cetera.

Ammonium hydroxide does not fit the list, since it formally does behave like a solution of the hydroxide salt of ammonium.

Pulverulescent - 7-2-2012 at 08:29

You're good! That's what you are! Good! (

)

P

Vikascoder - 7-2-2012 at 08:30

Ya this information is correct but why ammonium hydroxide is to be hated

Pulverulescent - 7-2-2012 at 08:32

'Cos it stinks? (

)

P

GreenD - 7-2-2012 at 08:45

it stinks, and there "is no such thing as ammonium hydroxide" !

There is ammonium
There is hydroxide

There is no ammonium hydroxide

any other examples of this? Urine and uranium I think is a stretch haha

[Edited on 7-2-2012 by GreenD]

turd - 7-2-2012 at 11:14

There is no point in examples since ALL of chemistry is like that. One reason is that many trivial names were coined when comprehension of the structure of matter was not very deep (e.g. carbohydrate, chloral hydrate), but.more importantly, because chemistry is about CONCEPTS. We don't care what it really looks like - what matters is how it reacts and how you can describe it. Think about the huge field of hydrous silicate and aluminate phases. Of course Al2O3.xH2O and SiO2.xH2O do not exist in that form - but describing them that way is very useful from a conceptual point of view. Likewise hypophosphorous acid may not exist (it's actually phosphinic acid), but both give rise to different, isolable derivates (esters). Or think about the synthons in organic chemistry. In the same vein, an ammonium hydroxide solution makes perfectly sense: if you add an acid it reacts like a solution of ... well ... ammonium hydroxide.

Edit: Oh, and some of the examples you gave simply come from the same root: chloros=green (obvious), phos=light (white phosphorus emits light, phosgene is created with light). That's where some general education helps.

[Edited on 7-2-2012 by turd]

madscientist - 7-2-2012 at 11:32

Ammonium hydroxide is real. Ammonia is basic, and gets protonated by water, leaving a hydroxide ion for each ammonium ion.

GreenD - 7-2-2012 at 12:13

Quote: Originally posted by turd

Edit: Oh, and some of the examples you gave simply come from the same root: chloros=green (obvious), phos=light (white phosphorus emits light, phosgene is created with light). That's where some general education helps.

[Edited on 7-2-2012 by turd]

I actually realized the chloro after posting. I hadn't known that phos = light. And bringing up carbohydrates - I now realize how prevalent this misleading nomenclature is!

DougTheMapper - 8-2-2012 at 16:29

A "phosphor" is a broad term describing a substance which will "fluoresce."

Most phosphors do not contain phosphor, and most fluorescent compounds do not contain fluorine. I believe phosphorus was named with the prefix "phos" because when it was first discovered it glowed (burned) in air. As for fluorescence, this term was derived from the phenomenon of glowing fluorite crystals because of a europium impurity and was originally thought to be the fluorite itself.

DDTea - 11-2-2012 at 19:01

How about theobromine, a xanthine derivative that contains no bromine.

arsphenamine - 12-2-2012 at 10:43

Quote: Originally posted by madscientist

Ammonium hydroxide is real. Ammonia is basic, and gets protonated by water, leaving a hydroxide ion for each ammonium ion.

In Analytic Chemistry class, we got complex equilibria beat into our
thick hormone-sodden undergraduate skulls, so excuse me if I prattle on.

Room temp pKb for NH3 is 4.75 which corresponds to 0.4% dissociation before you include activity coefficients.

This suggests there's a lot more NH3(aq) than NH4OH. Suggests? Like Hell! It's an irreducible fact.

RT solubility in water is ~30%, = ~18M, = 1:2 molar ratio of NH3 to H2O.

This means that any honest model of aqueous ammonia needs a coupla waters in the picture.
This empirical force field model tries hard to show the hydrogen bonding.

Ab initio modeling twists the water mols ~10 degrees out of co-planarity.

That's all for now.

arsphenamine - 12-2-2012 at 10:45

Quote: Originally posted by DDTea

How about theobromine, ...

It's all Greek to me.

thesourcerer - 11-3-2012 at 15:09

I don't see any problem with Bromine and Theobromine. Theobromine is an alkaloid from the species Theobroma cacao, and it is usual nomenclature to name an alkaloid from the plant and end in ine. The species Theobroma was named long before Bromine was discovered. They are both derived from the greek Bromos (stench), whilst Theo means god. Well I think cocoa (or chocolate) has a godly smell, but Bromine definitely stinks. cf Chlorophyll and Chlorine, both green and hence the names, but why should that insinuate any chemical connection?

Endimion17 - 11-3-2012 at 15:34

Bromine doesn't stink. Its scent it similar to chlorine and iodine, and if concentrated low enough, reminds of photographic development stores.

"Stench" is something hydrogen sulphide and impure carbon disulphide are described with. Not simple oxidizers that smell of disinfectants.

Magic Muzzlet - 11-3-2012 at 15:42

Quote: Originally posted by Endimion17

Bromine doesn't stink.

????

But then again I guess using a flame on glassware isn't classic either right.

You have either ruined your noses ability to smell or never used pure liquid Br2 because I cannot fathom how you can make that comment. Unless you are joking.

phlogiston - 11-3-2012 at 15:52

"rhodanide" has nothing to do with rhodium.

A befriended dietician says he gets uncountable numbers of patients that talk about their 'chloresterol' levels. I guess the 'chlor' makes it sounds more nasty than the correct spelling.

BromicAcid - 11-3-2012 at 18:37

When Mr. A.G. Lee sat down and wrote his work "The Chemistry of Thallium" he picked two very illustrative quotes that relate exactly to the problem at hand. These I have committed to memory:

Quote:

So now we can nail down these changeable humors and tell them to their faces what species and class they belong to. That is man's prerogative on earth: to call things by name and put them in a system. They cast down their eyes before him when he calls them by name, for to name is to command." - Thomas Mann

That quote contrasts beautifully with its companion:

Quote:

Wherever primitive man put up a word, he believed he had made a discovery. How utterly mistaken he really was! He had touched a problem, and while supposing he had solved it, he had created an obstacle to its solution. Now, with every new knowledge we stumble over flint-like and petrified words and, in so doing, break a leg sooner than a word. - Nietzsche