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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: eugenedakin on August 03, 2012, 09:15:51 PM

Title: Will freezing 30-35% Hydrochloric acid split totes like water does?
Post by: eugenedakin on August 03, 2012, 09:15:51 PM

Hello Everyone,

I have been asked a question and am having a difficult time finding the answer. In parts of Canada the temperature can reach -50 C which is below the freezing point of 30-35% hydrochloric acid. When this property change occurs, will the freezing of hydrochloric acid cause totes to mechanically fail? Water expands when it is freezing, and does this same aspect occur with 30-35% hydrochloric acid?

Thanks for your help :)

Eugene

Title: Re: Will freezing 30-35% Hydrochloric acid split totes like water does?
Post by: Arkcon on August 04, 2012, 07:34:59 AM

Generally, when something that is a mostly water solution freezes, the solution expands, just like water does.  Often, the solution crystallizes out at least some of the pure solute and pure water, (although mixed ice can occur, as well as ice with inclusions.)  A 35% solution of hydrogen chloride gas in water isn't a separate compound, unlike for example 98 % pure sulfuric acid.

Title: Re: Will freezing 30-35% Hydrochloric acid split totes like water does?
Post by: Hunter2 on August 06, 2012, 04:00:42 AM

For this reason some chemicals get storage conditions. So the barrels have to be transported  in an isolated warm container on the truck or ship.

In our product we have indicators on the barrel what shows the temperature. In our case the high temperatures in Asia or India are the problem.

In your case I would be careful, a broken hydrochloric barrel is a risk.

Title: Re: Will freezing 30-35% Hydrochloric acid split totes like water does?
Post by: BobfromNC on August 10, 2012, 04:23:07 PM

Just try Google, this is the first answer to "What is the freezing point of hydrochloric acid?"

http://wiki.answers.com/Q/What_is_the_freezing_point_of_hydrochloric_acid

"Answer:
-74 degrees Celsius (approximate minimum freezing point for 25% solution)

-20 degrees Celsius (approx freezing point for 10% solution which is a common household concentration)

Generally freezing point declines to a concentration of 25%, beyond that concentration the solution begins to crystallize more easily thus raising the freezing point"

So not much of a problem...

Title: Re: Will freezing 30-35% Hydrochloric acid split totes like water does?
Post by: AWK on August 11, 2012, 03:21:45 PM

http://en.wikipedia.org/wiki/File:Phase_diagram_HCl_H2O_s_l.PNG