[mafiaparty303]

It is balanced...

NaHCO₃ + HCl --> NaCl + H₂O + CO₂
 
One Na here,,,one over there....One Cl here...one Cl there. 2 Hydrogens on the reactants.... two on the products.....and then 3 oxygens,. One carbon there....one carbon here..

its balanced.

[AWK]

This is always the first step. Now the next one. What do you want to obtain - carbon dioxide or NaCl or both, or just to see bubbling?
Note, concentrated HCl is much more safe than H2SO4. Some people even drink a very diluted HCl (0.01M) as a drug  (concentrated HCl diluted 2000 times). But in every case use gogle for goodness sake

[mafiaparty303]

NaHCO3.... isnt that baking soda??used to neutralize the acid?

[billnotgatez]

http://en.wikipedia.org/wiki/Baking_soda

[mafiaparty303]

NaHCO3 + HCl ? NaCl + H2O + CO2 (gas)


So I was right 

[woelen]

If I read through this thread, then I still have the feeling that the dangers of HCl are strongly exaggerated.

Of course it is nasty stuff and of course one has to be careful, but the risks really are not as severe as this thread may suggest.
Even if you get it on your skin, you don't have serious burns at once. Just quickly rinse it away with lots of water and indeed, if you get it in your clothes, take them out and rinse the affected area of your skin with water. But that's all. No need to panic, conc. HCl does not burn in seconds, but in minutes, so you have the time to get rid of it.

The reason I write this, is that I think it is very important to differentiate between dangers. If everything is called "extremely dangerous", then really dangerous situations can occur.
Suppose HCl is described as extremely dangerous. But after some time, person XXX works comfortably with it, and even if small accidents happen with the acid, he simply cleans up, and no ill effects.
A few months later, person XXX acquires some 20% HF, which also is described as  extremely dangerous. Person XXX knows what "extremely dangerous" means for HCl, so he treats the 20% HF in the same way. Person XXX has some small accident with the HF, similar to the accidents he had with the HCl. A few hours later, person XXX is no more....

Moral of the story: Classify chemicals, according to danger. I would call conc. HCl a moderately dangerous chemical. It is quite corrosive and must be treated with respect, but there are other MUCH more dangerous chemicals (e.g. conc. H2SO4 already is more dangerous, conc. HF is insanely dangerous).

I myself work comfortably with conc. HCl. I also work on a regular basis with conc. H2SO4, although with that I am already much more careful. HF is something which is not in my homelab, and never will. I simply feel not confident that I ever can work safely with that material.

And finally, a nice tip if you need to store the acid.
Take out some acid in a small glass bottle (e.g. 100 ml) with a plastic cap. Use this as working amount.
Put the remaining jerrycan (or large bottle) of acid in a thick plastic bag and tightly bind this up. Put another plastic bag around this and tightly bind this up. Put the acid with the two bags in a dry and not too cold place. This works perfectly well for me. I noticed, that HCl is corrosive to nearby things, if they can become humid. In dry and not too cold air, I never had such problems. Having the two bags around it makes emission of the acid almost neglectable.

[constant thinker]

I like the two bag idea. I went and did that with my 98%+ H₂SO₄. I have a small amount (~25-50ml) in a little glass bottle that has a dropper in the cap. That's the bottle I work with for experiments. The main bottle is a 250ml bottle.

I have to agree with the HCl and HF scenario presented by woelen. Can the average home chemist even buy the stuff (I have no intention of ever getting it)?

[Borek]

I have to agree with the HCl and HF scenario presented by woelen. Can the average home chemist even buy the stuff (I have no intention of ever getting it)?

HCl - no problem

HF - even if you can't buy it, you have to be carefull when working with fluorides in acidic solutions.

While I have adressed some HCl dangers and adviced to use coat I wholeheartedly agree with Wilco.

[pantone159]

I've seen HF listed at more than one place that I could buy from, but I'm with Woelen in that stuff ain't getting anywhere near my lab.

[joeflsts]

Hey Mark,

Yep, read this -

http://www-safety.deas.harvard.edu/advise/accident.html

Find the header "Accident Description".  This one will describe just how "simple" accidents happen.

Jole

[mike]

Moral of the story: Classify chemicals, according to danger. I would call conc. HCl a moderately dangerous chemical. It is quite corrosive and must be treated with respect, but there are other MUCH more dangerous chemicals (e.g. conc. H2SO4 already is more dangerous, conc. HF is insanely dangerous).

Hydrochlorice acid: Classified as hazardous according to the criteria of EU Annex 1 and NOHSC. Causes burns and irritating to respiratory system.

Hydrofluoric acid 50%: Classified as hazardous according to the criteria of EU Annex 1 and NOHSC. Very toxic by inhalation, in contact with skin and if swallowed. Causes severe burns.

Just read the MSDS before you use any chemical (as I have stated before), this way you can make up your own mind without relying on other peoples opinions.

[woelen]

To my opinion, MSDS's are not the best source of information. Dangers are exaggerated too much and the there is not sufficient discriminating power between MSDS's. That is exactly what I wrote in my previous post.

of course, you can skim an MSDS to get an impression, but if you compare MSDS's of e.g. table salt and hydroquinone, then both compounds seem equally risky. Well, I can assure you that hydroquinone is more risky (albeit still not that risky). Even if I read the MSDS of table salt, and I put besides that the one for NaCN, then I may get the impression that if such strong words are used for table salt, then NaCN, although somewhat more dangerous, is not that bad. You all know otherwise.

Also, what irritates me is the listing of incompatibles in many MSDS's. They are full of warnings for violent and explosive reactions. I must say, I have tried numerous ones of these, and in 99% of all cases nothing happens. These warnings always are for the most extreme conditions. As an example, K2Cr2O7 is incompatible with plastics. Yes, K2Cr2O7 may react violently with plastics at 1000 C during a fire, but normally it doesn't (it even is shipped in plastic bottles). MSDS's do not mention the conditions for such reactions. In case of fire, almost any chemical is dangerous and then even table salt can give rise to really nasty compounds in combination with certain organics, such as present in common household waste.

What I am missing is a really good source of documents, which mention the dangers of chemicals.

[pantone159]

MSDS are written for lawyers, not chemists, unfortunately.  Many of them are quite useless, IMHO.

The Journal of Chemical Education has been putting out a series of chemical information sheets called CLIP, that is an attempt for a more useful MSDS-replacement.  I couldn't figure out how to attach files, so some links to some examples:
http://lochkness.com/CLIP/CopperSulfate.pdf
http://lochkness.com/CLIP/Glycerol.pdf
http://lochkness.com/CLIP/Sodium.pdf
http://lochkness.com/CLIP/SodiumThiosulfate.pdf

These tend to be more useful than most MSDS.  However, some MSDS are better than others.  Ones that have a numeric code, 0-4, quantifying the hazards, I like.

[mike]

Even if I read the MSDS of table salt, and I put besides that the one for NaCN, then I may get the impression that if such strong words are used for table salt, then NaCN, although somewhat more dangerous, is not that bad. You all know otherwise.

The MSDS for NaCl makes it quite clear that it is no where near as dangerous as NaCN, have you read the MSDS for these compounds? Surely you would agree that the MSDS tells the reader quite clearly that NaCl is not classified as hazardous, while NaCN is classified as hazardous. Also the lethal dose for NaCl is enourmous in comparison to the lethal dose of NaCN.

I think that your point is that HCl is not as dangerous as everyone is saying, however this depends on the circumstance. The truth is people have been seriously hurt using HCl (ie loss of eye sight as an example). The best thing to do is not take liberties with any chemicals.

With MSDS, check the hazard rating and what the hazard classification is (toxic, corrosive etc etc) check the lethal dose as this will give you an idea of the potency, check the routes of exposure (breathe, skin, mouth etc), check the exposure limits (how long can you be exposed before suffering some injury).

Mike

[pantone159]

The MSDS for NaCl makes it quite clear that it is no where near as dangerous as NaCN, have you read the MSDS for these compounds?

It depends on the particular MSDS.  Some go on and on with 'boilerplate' warnings that are so verbose that they effectively obscure the very important fact that one is a LOT more hazardous than the other.  (Then there are those printed in ALL CAPS, who's idea was that?)
Some MSDS do a much better job, however.