Does MA go bad/loose strength?

y_not

0
Jul 24, 2012
1,084
Redmond, OR
I'm curious on a couple of things relating to MA.

1. Say I find a bottle of MA that's of unknown age at a yard sale or what not, assuming it is tightly sealed and hasn't been left in the sun, if that latter part even matters, does it loose it's strength after several years, or many years, or what not?

I found a bottle of Klean Strip, non green junk, I opened it up and it was a mega WHOOSH! of acid smell, choked me for a moment, much stronger than my own MA that's fresh, same BAUME/%. I'm assuming because it has had a chance for those vapors to really build up in there?

2. I have read on here that MA is the same as Hydrochloric Acid, however I had someone tell me that this is true, except that HA is much more pure, cleaner, free of impurities than MA is. MA is very chemically dirty, lots of junk in it. What junk, I don't know.
Is this true?

Thanks. :)
 
Muriatic Acid is just a historical name for hydrochloric acid. It isn't filled with junk. It has water. The one you opened that went whoosh probably did not have a functioning pressure relief valve in its cap so when you opened it when it was apparently under pressure, the hydrochloric acid gasses escaped quickly which was overwhelming. Even a properly capped bottle of full-strength Muriatic Acid (31.45% Hydrochloric Acid) when opened can have very strong vapors.
 
So does it go bad, break down in the bottle?

Naw, it didn't whoosh like an air blast, it was just a stronger vapor blast than I have experienced before.
But probably the same thing, just thought I'd clarify for the heck of it.
 
What about the storage environment... does it have any effect?
I live in Phoenix and am considering puting a storage box out by the pool to store the supplies ... chlorine, MA, etc.

I've read where chlorine will age and lose it's strength. Does it age any quicker when stored in a hot box?
 
It shouldn't matter with Muriatic Acid which is hydrochloric acid with water. It's stable. However hotter temps will increase the pressure in the bottle and the cap has pressure relief so some gas will escape so if you have any metal components in the box then they will likely rust. That could happen in general anyway which is why one shouldn't store acid near metal and should store it in a well-ventilated place.
 
Next MA storage question....are low temps/freezing an issue? I'd like to store my leftover this winter eithr outside undr my deck where I store it now or in a unheated garage.

Although I suppose if it goes bad I'm out less than a galloon which is about four bucks.

Sent from my Exhibit II using Tapatalk.
 
Smykowski said:
Next MA storage question....are low temps/freezing an issue? I'd like to store my leftover this winter eithr outside undr my deck where I store it now or in a unheated garage.

Although I suppose if it goes bad I'm out less than a galloon which is about four bucks.

Sent from my Exhibit II using Tapatalk.
I'd be more concerned that the jug would split and spill acid all over the place.
 

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y_not said:
So the acid doesn't keep the water from freezing solid, like sugar does?
I'd really hate to store acid in my house.
I left a full jug outside this past winter. We had a relatively mild winter but there were times when we had a couple inches of ice on the pool in January. Jug is still fine.
 
Before owning a pool, I kept a jug of MA in a plastic bag on a metal shelf. Ate the shelf it was sitting on nearly all the way through. Yeah, not too much longer and it would have fallen 4' to the floor and split. Parked the car right there too. Had to throw the 5 level shelves away. I had no idea that it was passing through the plastic bag.
 
anonapersona said:
Before owning a pool, I kept a jug of MA in a plastic bag on a metal shelf. Ate the shelf it was sitting on nearly all the way through. Yeah, not too much longer and it would have fallen 4' to the floor and split. Parked the car right there too. Had to throw the 5 level shelves away. I had no idea that it was passing through the plastic bag.

WOAH!!! So it was in the HDPE white jug, plus inside a plastic bag as well and it wept through both materials?
The bag I can see, as it's not going to be chemical resistant typically, but the HDPE jug? They're impervious to chemicals and relatively high heat as well as cold and UV resistant. It's one amazing polymer. Was there a leak? IE. did the jug freeze and split open, then go through the plastic bag?

Yeah, hydrochloric acid on metal is BAAAAADDD!! You can cut a car in half with that stuff. LOL
My dad used to build black powder percussion muzzle loaders and he'd etch the barrel /w tar, engrave his name in the tar, then pour HCL on it and let it bubble away, then he neutralized it with baking soda.
Pretty stinkin cool!! :mrgreen:

So glad it didn't get on your car though. That would have been a spendy repair. :shock:
 
chem geek said:
As described in this post, the freezing point of full-strength Muriatic Acid (31.45% Hydrochloric Acid) is -46ºC (-50.8ºF). Half-strength Muriatic Acid (15% Hydrochloric Acid) has a freezing point of -18ºC (-0.4ºF).

I didn't even see this post initially for some reason. As always, you have come to the rescue with the technical data we need to satisfy our nerdy quests and questions. ;)

I did find this: Bayer 20 baume 32% MA/HCL Solution MSDS

On pg. 4 it shows the following.
Code:
Form: liquid 
Color: Colorless to light yellow 
Odor: Pungent, strong 
pH: < 1.5  Acidic, In solution 
Freezing Point: Approximately -45 °C (-49 °F)  
Boiling point/boiling range: 81.11 - 85 °C (178 - 185 °F)
<..snip..>

So they quote it as 49deg Fahrenheit for us USA folks.
Right inline with what you posted.

So I'll just leave it outside, as I'd prefer to keep it out of the house. It's pretty nasty stuff. :stirpot:
 
y_not said:
WOAH!!! So it was in the HDPE white jug, plus inside a plastic bag as well and it wept through both materials?
The bag I can see, as it's not going to be chemical resistant typically, but the HDPE jug? They're impervious to chemicals and relatively high heat as well as cold and UV resistant. It's one amazing polymer. Was there a leak? IE. did the jug freeze and split open, then go through the plastic bag?
It doesn't go through the HDPE. It goes through the VENTED cap. The cap is intentionally vented so that if the temperature goes up then the bottle won't burst. However, this means that some hydrochloric acid gas can escape through the cap. In essence, the cap "breathes" somewhat and the cap may not be perfect either so may let some acid gas out of the bottle over time. It only takes a fairly small amount of hydrochloric acid gas to corrode metal because it is so very strong. Your nose knows how strong as well, but unlike chlorine, your sensitivity to it doesn't usually detect the very low levels that might escape. You can put a moist pH strip near the bottle cap to see if it is currently venting gas.
 
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