Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: dr.satan on 14/05/2007 21:03:57

Title: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: dr.satan on 14/05/2007 21:03:57
Has anybody ever experimented with H2So4 on Salt (sodium chloride to be official), or any other halide salt - sodium bromide, sodium iodide (peeeewww [xx(] [xx(] what a stink the H2S produces, that wasn't too much fun in my back garden. Anyways i was wondering if anybody buys it, where do they get it from? my source was a friend who is a chemistry teacher at a sixth form college, much fun to be had with concentrated acids!!!  [:)] [:)] [:)] [:)]
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: another_someone on 14/05/2007 21:17:29
You are aware that H2S is highly poisonous?

Yes, I know, in my schooldays we had plenty of people who plaid around with it, and thought it was fun, and as far as I am aware, none died from it; but do be careful about exactly how much you do breath in.
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: Bored chemist on 14/05/2007 21:36:33
HCl, HBr and HI are not exactly good for you. I once managed to burn my arm with H2SO4 and I can assure you that's not fun either.
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: dr.satan on 14/05/2007 21:49:45
In an open air enviroment its all good, never do it without a vented place thats for sure, and yes i know it is not fun to be burnt with H2SO4, my fingers have paid the price for my passion for science many times, can i ask how to do sub/super scripts, its easier for writing out chemical formulas
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: another_someone on 14/05/2007 22:27:58
can i ask how to do sub/super scripts, its easier for writing out chemical formulas

You might want to read http://www.thenakedscientists.com/forum/index.php?action=help;page=post#bbcref

Specifically: you precede the subscript with [sub] and succeeed it with [/sub].   You precede the superscript with [sup] and succeeed it with [/sup]
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: DrDick on 15/05/2007 16:25:41
Has anybody ever experimented with H2So4 on Salt (sodium chloride to be official), or any other halide salt - sodium bromide, sodium iodide (peeeewww [xx(] [xx(] what a stink the H2S produces, that wasn't too much fun in my back garden. Anyways i was wondering if anybody buys it, where do they get it from? my source was a friend who is a chemistry teacher at a sixth form college, much fun to be had with concentrated acids!!!  [:)] [:)] [:)] [:)]

Actually, you don't produce H2S with this experiment.  You create HCl (or HI or HBr).  They are still pretty noxious fumes, however.  I remember doing this in college, but we had a fume hood to use, so we didn't have to smell the fumes.

And you can sometimes get concentrated sulfuric acid from the hardware store.  Some people use it to remove stumps, etc., because it reacts pretty strongly with organic matter.  Contrary to popular belief, however, it's not a very strong oxidizing acid.  It IS a very strong dehydrating agent (removing the "hydrate" from "carbohydrates", as it were).

Dick
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: Bored chemist on 15/05/2007 19:19:33
H2SO4 is a strong enough oxidising agent to oxidise HI. In doing so some of it is reduced to SO2 and H2S.
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: dr.satan on 15/05/2007 21:22:51
H 2 S can be a product of this reaction, and although very minute quantities are produced - the stink is still very substantial with a pile of sodium iodide, and thanks DrDick anyway, i will look in hardware stores!
Title: Re: How does sulphuric acid (H2SO4) react with sodium salt (NaCl)?
Post by: DrDick on 16/05/2007 18:04:19
H2SO4 is a strong enough oxidising agent to oxidise HI. In doing so some of it is reduced to SO2 and H2S.

With iodide, you're correct, but the oxidation of iodide is relatively easy.  Having said that, if you look up the standard reduction potentials, the process is not spontaneous (unfavorable) under standard conditions (1 mol/L concentration of each).  It's only when the concentrations (of H2SO4 and I) are relatively high (as is the case in pure H2SO4), that the reaction proceeds.