Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
Member Is Offline
Mood: Slowly getting ready for new projects
|
|
Zinc + impurities in HCl - worries about heavy metal hydrides
So, I've heard that nascent hydrogen can oxidize antimony and arsenic impurities to stibine and arsine respectively which I don't want to experience.
I am worried that my hardware store HCl might contain such impurities, though, and since I want to dissolve some zinc in it I am not sure if it safe.
Are my worries realistic?
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
|
|
|
Bedlasky
International Hazard
Posts: 1219
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
Don't worry, main impurity in technical HCl is iron. Sb or As contamination is unlikely. I dissolve zinc or aluminium in technical HCl many times and
I still live.
Btw. nascent hydrogen can reduce almost any nonmetal and metalloid (and sometimes metal such as tin) in to hydride.
|
|
|
unionised
International Hazard
Posts: 5102
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
With technical grade zinc and acid, the production of small amounts of things like PH3 AsH3, H2S and SbH3 will happen.
These compounds are responsible for the smell associated with H2 produced from acids and metals.
If you need to get rid of them you can bubble the hydrogen through a solution of KMnO4 or some such.
But the quantities present are usually so small that you don't need to worry about them.
That doesn't mean that it's a good idea to sniff the hydrogen in large amounts.
|
|
|
Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
Member Is Offline
Mood: Slowly getting ready for new projects
|
|
Ah, alright. Thanks.
Also, I can't believe I said that nascent hydrogen oxidizes.
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
|
|
|
Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
Member Is Offline
Mood: Slowly getting ready for new projects
|
|
Just threw a few pieces of zinc into my HCl. I hope the fact that the room filled immediately with a tarry, stinging smell doesn't mean that the
quality control of the HCl producer messed up and that I won't end up with lung edema and severe haemolysis.
[Edited on 16-7-2020 by Draeger]
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
|
|
|
Draeger
Hazard to Others
Posts: 185
Registered: 31-1-2020
Location: North-Rhine Westfalia, Germany
Member Is Offline
Mood: Slowly getting ready for new projects
|
|
A worrying thing I have noticed is that there seems to be a dark metal mirror that has formed symmetrically adjacent to the surface of the reaction
mixture. This could either be zinc that has been pulverized by my stir bar, or maybe whatever hydrides were formed have decomposed to the
corresponding metal. It's a small mirror, though, so maybe there still weren't more hydrides than usual, I hope.
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
