Sciencemadness Discussion Board - How come I can smell bleach?

How come I can smell bleach?

kerousel - 29-8-2009 at 23:47

I want to evaporate some bleach solution, to get powder NaOCl ... Anyways I was wondering, how come I can smell bleach? NaOCl is a salt it doesn't evaporate (it decomposes at 101 C), and since it's in water it's not like I can smell tiny particles of it in the air... So what gives? Is it like there's an equilibrium NaOCl + H2O > NaOH + HOCl and I can smell the HOCl?

not_important - 30-8-2009 at 00:34

Yes. And HOCl is such a weak acid that CO2 can displace it from its salts, even the CO2 in air.

On top of that you can't get NaOCl by evaporating it at ordinary temperatures. You have to concentrate it under reduced pressure, and crystallise out the NaOCl as a hydrate by chilling the solution; it melts at room temperature. The solid is not very stable so you'll not get it in powdered form.

kerousel - 30-8-2009 at 00:48

ah, shucks. You're right, I can't get anhydrous NaOCl, the temperature for it to dehydrate is probably higher than for NaOCl to decompose...

2CO2 + 2NaOCl > 2NaCO3 + Cl2
Right that makes sense. I wonder if acetic acid on NaOCl makes acetic anhydride/

kclo4 - 30-8-2009 at 00:54

Why would it?

This is the reaction that would happen if water were present:
CO2 + H2O = H2CO3
H2CO3 + NaOCl = Na2CO3 + 2 HOCl
2 HOCl = H2O + Cl2

[Edited on 30-8-2009 by kclo4]

kerousel - 30-8-2009 at 01:06

Oh right it wouldn't make acetic anhydride, it would make acetyl chloride in presence of CO2 or HCl I guess.

Quote: Originally posted by kclo4

2 HOCl = H2O + Cl2

???

[Edited on 30-8-2009 by kerousel]

kclo4 - 30-8-2009 at 01:14

Oh you are right, that isn't balanced... well it decomposes some how into water and chlorine and something else..

Must release O2 as well or produce chlorous or chloric acid?

NaOCl + RCOOH = RCOONa + HOCl

How is it you are thinking sodium hypochlorite will produce aceyl chloride? Show me the reaction you have in mind.

[Edited on 30-8-2009 by kclo4]

kerousel - 30-8-2009 at 01:24

Ahh I don't even know, acetyl chloride hydrolyzes to HCl and HAc anyways, right? So it wouldn't work.

But what I had in mind was NaAc + Cl2 = AcCl + NaCl. Or something like that.

**btw just mixed some 3%bleach and 5%acetic acid. No chlorine noted. Too low concentrations?

**also apparently I'm an idiot, Ac in AcCl is not the same as in HAc.

[Edited on 30-8-2009 by kerousel]

kclo4 - 30-8-2009 at 01:40

Most likley it is to low of a concentration to kick off the chlorine, since chlorine is fairly soluble and 3% and 5% is not very concentrated at all.
Aceyl chlorides and anhydrides are not easy to make at all. Best bet uses anhydrous sodium acetate, sulfur chlorides, bromine, etc. You should be able to find it on erowid, its not hard to find at all. Titled something acetic and propionoic anhydride? Google around a bit.. I won't give you a link.

HAc I assume is meant to be acetic acid?
look at this:
"The most common and official abbreviation for acetic acid is AcOH or HOAc where Ac stands for the acetyl group CH3−C(=O)−"

Wouldn't hurt to read up on some chemistry and get a better grip on what is actually going on

kerousel - 30-8-2009 at 01:58

Right, right I just noticed that mistake. I'm not actually trying to make acetic chloride I was just wondering about this HOCl, I think the thing is if you add an acid to it, i.e. HR, it would be in equilibrium

With HR being hydrochloric acid, it will get you loads of chlorine gas, with HR being acetic acid it won't get you acetyl chloride because the other side of the equilibrium will be favored.

[Edited on 30-8-2009 by kerousel]

kclo4 - 30-8-2009 at 02:10

What mechanism, reaction, equation, etc would even make it produce acetyl chloride?
Like I asked earlier, what is it you have in mind? NaOCl + CH3COOH = CH3COCl + ?
Its probably not an equilibrium thing, I don't even think that reaction can happen.

The way you put it, pretty much all reactions are in some form of an equilibrium...

kerousel - 30-8-2009 at 02:19

Nevermind, not only it wouldn't work in real life but it doesn't even work in theory... forget I ever said anything about it, I just realized I had some mistakes in non-balanced equations, forget about it...

[Edited on 30-8-2009 by kerousel]

entropy51 - 30-8-2009 at 07:12

Quote: Originally posted by kerousel

Ahh I don't even know, acetyl chloride hydrolyzes to HCl and HAc anyways, right? So it wouldn't work.

But what I had in mind was NaAc + Cl2 = AcCl + NaCl. Or something like that.

**btw just mixed some 3%bleach and 5%acetic acid. No chlorine noted. Too low concentrations?

**also apparently I'm an idiot, Ac in AcCl is not the same as in HAc.

[Edited on 30-8-2009 by kerousel]

Are you are an idiot? Or just lazy? Now get a chemistry book and do something about it. You shouldn't be clogging up this forum with questions that most high school chemistry students would recognize as dumb.

kclo4 - 30-8-2009 at 12:02

Quote:

Are you are an idiot?

Oh, let me answer that question for you!

This person is carbon chloride, the one who wanted to make lefetamine out of 1,2-diiodo-ethanol and benzene via an impossible reaction he made up out of thin air.

http://www.sciencemadness.org/talk/search.php?token=&srchtxt=&srchfield=body&srchuname=carbon+chloride&f[]=all&srchfrom=0&filt er_distinct=yes&searchsubmit=Search

He's been over at The Vespiary as rocketman, pippylongstockings and D. Rich Kerlikowske. He's made attempts to sign up as kclo4 as well, but the name is reserved and so he failed, however he did sign up with kclo4@hotmail.com using pippylongstockings as an account.

Pippylongstockings, when asked admitted to being kerousel.

Here is all the information I can find about him attached in a wps. document. I've been keeping little notes since I noticed he was being a brat.

Kerousel, sorry if this isn't you - in that case, you have someone claiming they are you.

Attachment: rocketman.wps (134kB)
This file has been downloaded 520 times

entropy51 - 30-8-2009 at 12:11

Let's ask Polverone to make a chemistry question part of the registration process for new members. Something along the lines of

Vinegar + table salt ->

(a) acetyl chloride
(b) sodium acetate
(c) sodium chloroacetate
(d) salty vinegar

DJF90 - 30-8-2009 at 12:56

That would be a great idea entropy! But surely we could make it slightly harder?

entropy51 - 30-8-2009 at 13:08

Something like this perhaps?

Cl2 is which of the following:

(a) a transition metal
(b) an ionic solid
(c) a halogen molecule
(d) the sticky stuff that you want to know how to get out of your sudafed pills

DJF90 - 30-8-2009 at 13:26

Hmm possibly.. Again I think that is too simple. Perhaps ask them to write a balaced equation for the reaction between an acid and an metal (alkali/alkaline earth) a) oxide b) hydroxide and c) the metal itself. This is basic textbook stuff.

entropy51 - 30-8-2009 at 13:29

I suppose we will be accused of being too elitist. Sigh.

kclo4 - 30-8-2009 at 17:28

Yeah, it is best to deal with them as they come I suppose? A lot of us were noobs, and they really aren't that bad as long as they are willing to learn. Thats the problem though, a lot of them are not willing to learn at all, and instead become malicious when we show them a better method, or why their crazy little ideas won't work and suggest they learn just a bit more.

Anyways, I just got a message from him, with his new account now being kсlo4, obviously named after me.

Quote:

you're a douche vesp.

you think i really care about my reputation on this site? i've had like 3 accounts and never gotten above like 20 posts. Even less than I care about your small site.

not to mention, even if I wanted to I have several hide IP programs to change my ip. oops my ip is 65. oops it's 76. oops it's 127. you'd never even know it's me.

not that I plan to because I do have a life. I'm 16 btw, how old are you? 21-23?

and don't bother responding because i'm out of here.

Like it takes an IP address to figure out who it is posting such things. Anyways, I guess I'll stop talking about him since this thread is distracting to the other more important threads. I still can't get over how he thinks I'm a douche though, I tried to answer his questions and help him learn things, and I haven't even completely ban him from my site. Oh well.

Rich_Insane - 31-8-2009 at 13:27

Wait, vinegar + NaCl makes something? I thought it makes only salty vinegar (Vinegar and Sea Salt chips)..... I would be quite scared of eating those if it made Acetyl chloride.........

Sedit - 31-8-2009 at 14:55

Yeh this does seem typical of Rocket_man KClO4. The question starts as a decent newbee question the detours into a realm of insane what ifs. And I almost felt bad for telling carbon chloride where to stick it when he was ashamed to be a post whore over there.

Rich_Insane - 1-9-2009 at 12:30

So no, it doesn't make anything?

VestriDeus - 15-11-2009 at 13:09

Quote: Originally posted by Rich_Insane

Wait, vinegar + NaCl makes something? I thought it makes only salty vinegar (Vinegar and Sea Salt chips)..... I would be quite scared of eating those if it made Acetyl chloride.........

It only makes salty vinegar

It wouldnt make Acetyl Chloride, cause the chlorine wouldnt replace the OH. (though it would be cool if it were like:
CH3COOH + NaCl --> CH3COCL + NaOH )

entropy51 - 15-11-2009 at 14:03

Quote: Originally posted by VestriDeus

It only makes salty vinegar

It wouldnt make Acetyl Chloride, cause the chlorine wouldnt replace the OH. (though it would be cool if it were like:
CH3COOH + NaCl --> CH3COCL + NaOH )

Why not? Cl replaces OH all the time, as in

EtOH + HCl -----> EtCl

bbartlog - 16-11-2009 at 07:40

By the way and for what it's worth, you *can* dehydrate NaOCl to get some dry NaOCl, even without vacuum; for example, by heating it in an oven in a flat pan at 70 deg C or thereabouts. I've done it entirely by accident, while trying to dry what I thought was just a solution of sodium acetate (leftovers following the haloform production of CCl3, but with an unintentional excess of NaOCl; I recommend using acetone in excess instead). Lots of fun when I then tried to turn the resulting dry mass into NaCl and acetic acid by the addition of HCl.

No guarantees as to yield, though - I'm sure a fair bit of Cl is lost to the air.

[Edited on 16-11-2009 by bbartlog]

unionised - 16-11-2009 at 11:41

It's a whole lot more likely that you made NaClO3 (s) than NaOCl (s) that way.
Also you are fairly lucky that the intimate mixture of chlorate and acetate (a fuel) didn't decide to decompose violently.

bbartlog - 16-11-2009 at 19:00

You may well be right. As for the decomposition, I estimate I started with about 4:1 sodium acetate to sodium hypochlorite, so if the reaction 3NaOCL -> 2NaCl + NaClO3 took place it would still only have given sodium acetate:sodium chloride:sodium chlorate in a 12:2:1 ratio, which sounds... kind of inert. At least in terms of decomposing itself.
It did, however, give off nasty chlorine fumes when I added HCl. If you're right there was probably some ClO2 mixed in there as well. And when I had the bright idea of adding some acetone to try to finish the haloform reaction and get rid of the (presumed) NaOCl, I must have produced some chloroacetone, because that was quite a lachrymatory product. I still have a little (acetone plus I guess chloroacetone) in a jar.