Date: Fri, 30 Mar 2007 21:23:31 -0400
Reply-To: chemcon**At_Symbol_Here**JUNO.COM
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Jay Young <chemcon**At_Symbol_Here**JUNO.COM>
Subject: Re: Storing Nitric and Hydrochloric Acids
Comments: To: LDMcLouth**At_Symbol_Here**LBL.GOV
When they are mixed, nitric and hydrochloric acids do NOT react
exothermically, nor explosively.
The only significant consequence is that the mixture of the two, called
"aqua regia", is a strong oxidizing acid, strong enough to oxidize gold,
for example.

But on the other hand, a simple aqueous solution of sodium chloride will
oxidize gold if you bubble air into the mixture of gold and NaCl

To summarize, I see no significant hazard in the mixture of hydrochloric
and nitric acids which is greater than the hazards presented by the
individual unmixed, separate, acids.  In my opinion, there is no good
reason to separate the two in storage.

Jay A. Young
On Thu, 29 Mar 2007 14:00:38 -0700 "Larry D. McLouth" 
> What is your practice for storing  nitric and hydrochloric acids?  Do 
> you keep them separated to prevent mixing?
> I realize they are intentionally mixed to make aqua regia, (under 
> controlled conditions using a fume hood).  But this evolves chlorine 
> and 
> nitrosyl chloride there is a concern about storing these 
> two 
> acids together.
> I plan to tell our users that it's okay to keep these two acids in 
> the 
> same storage cabinet but that they should be kept on the same shelf 
> and 
> in individual photo trays to prevent accidental mixing in the event 
> of a 
> spill, leak etc.

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