Expert: Dr. Henry Boyter, Jr. - 6/16/2006

Question
What do you get if you mix hydrogen chloride with
phosphoric acid.

Is it dangerous, and if so why.  

Answer
You don't mention the concentration of the phosphoric acid or the form fo the hydrogen chloride so I am assuming here concentrated acid and gaseous hydrogen chloride.  Search google.com for the MSDS of each.  First, both of these chemcials are dangerous on their own.  Mishandling can lead to injury or death.  When mixed, if in a stainless steel container or if metal impurity is present, hydrogen gas can be liberated which is very flammable.

Using different forms and different concentrations will vary in the level of safety problems.  In highly dilute solutions the mix would not be a problem, but hydrogen chloride gas is always a problem.

The opinions expressed are those of Dr. Boyter and
are provided for informational purposes only and
should not be used as advice.  No warranty or
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