Sciencemadness Discussion Board

Shelf life of Ammonia and Muriatic acid

nannah - 17-4-2014 at 11:12

Hi, guys. I just wanted to drop in and ask if you guys know what shelf life for Muriatic acid and Ammonia?

Today when i was visiting my grandmother, i found two plastic bottles in the garage. They were covered in dust. They must have been there for a long time.
One of the bottles had its label peeled off so i couldn´t read it, but i think it is Muriatic acid. The other one were 25% Ammonia.

I was wondering if Ammonia and HCl expire and turns bad after a while? Becouse my HCl is kind of yellow in color, and all the HCl i have ever seen were transparant, like water.


Btw, somebody know if there is a way to find out if it is Muriatic acid i got?

Thanks in advance. :)

[Edited on 17-4-2014 by nannah]

[Edited on 17-4-2014 by nannah]

elementcollector1 - 17-4-2014 at 11:14

If it's yellow, it's got iron contamination. If the bottle was kept in a cool area and tightly capped, it should be fine (this goes for ammonia too).

copperastic - 17-4-2014 at 11:15

Nannah i found some old HCl in my basement and it was yellow too. I don't know what that means though. You could try reacting it with aluminum and if it fizzes it might be HCl.

copperastic - 17-4-2014 at 11:19

My above post was wrong because sulfuric acid and other acids fizz hydrogen when reacted with aluminum.

DraconicAcid - 17-4-2014 at 11:27

If HCl is contaminated by iron or copper salts, it will be yellow.

If it is HCl, it will react readily with aluminum foil (although copper will catalyze this), and it will slowly corrode copper when exposed to air (put some wire into a beaker, pour in just enough acid to cover it, let it sit for a day. If it foams and gives off horribly toxic brown gas, then it's nitric acid or aqua regia, not hydrochloric). The acid will also be volatile (pour some into a beaker, pour some of the ammonia into another beaker, and hold them close together. Lots of white fumes means you have a volatile acid, which will not be sulphuric).

If it's concentrated hydrochloric acid, you can test for that with a saturated solution of salt. Take a few mL of saturated sodium chloride, and add your muriatic acid. If it's truly concentrated, a few drops will give a precipitate of salt. If it's not quite concentrated, you may have to add a bit more. If you don't get any precipitate, then it's either dilute, or a different acid.

LanthanumK - 17-4-2014 at 15:29

I found an old opened bottle of 20% or so hydrochloric acid at my grandmother's house. It was highly potent, though somewhat yellowed. The bottle will leach fumes but the acid will not decrease in acidity measurably if sealed properly.

woelen - 17-4-2014 at 22:42

Both hydrochloric acid and ammonia have infinite shelf life if they are stored in well-sealed bottles.

sasan - 17-4-2014 at 23:06

It is better to store in the colored bottles like amber glasses.Recently I change my colorless plastic bottle of 37%HCl,because when I pressed the bottle with my fingers,It broke like a glass,it got somewhat inflexible in the presence of HCl

Most of the chemicals if stored in a suitable conditions and bottles,have infinite shelf life,and some have a short life,like complexes,hygroscopic materials,biochemicals and ...

HgDinis25 - 18-4-2014 at 02:49

Sasan, what was your bottle made of? AFAIK, most plastic won't be affected by HCl at any concentation. I can't remember a single one affected by it. Only CAB gets slighty affected but on passing years only.

sasan - 18-4-2014 at 05:23

Hgdinis 25 it was made of poly ethylene I think
I'm wondering too why the bottle got inflexible,as a matter of fact,before I place the HCl in it,there was rhodium sulfate and dilute sulfuric in the bottle

nannah - 18-4-2014 at 05:57

Quote: Originally posted by elementcollector1  
If it's yellow, it's got iron contamination. If the bottle was kept in a cool area and tightly capped, it should be fine (this goes for ammonia too).


That was my first thought, but the bottles cap was sealed. The bottle has been there for years.
Is there any way to get rid of it? I´m checking it right now.

I read that you can concentrate Ammonia using gas washing. That was pretty cool.
Quote: Originally posted by woelen  
Both hydrochloric acid and ammonia have infinite shelf life if they are stored in well-sealed bottles.


Yes, that sounds right. I changed the bottle yesterday, into a HDPE bottle.
When i poured it over into the funnel it fumed just like the HCl i have had before.

Burner - 18-4-2014 at 07:14

Quote: Originally posted by sasan  
Hgdinis 25 it was made of poly ethylene I think
I'm wondering too why the bottle got inflexible,as a matter of fact,before I place the HCl in it,there was rhodium sulfate and dilute sulfuric in the bottle


I am guessing that the bottle might have been LDPE and may have had extensive sunlight exposure. I have seen that happen before, though it should not occur.

Texium - 18-4-2014 at 08:55

Quote: Originally posted by nannah  
Quote: Originally posted by elementcollector1  
If it's yellow, it's got iron contamination. If the bottle was kept in a cool area and tightly capped, it should be fine (this goes for ammonia too).


That was my first thought, but the bottles cap was sealed. The bottle has been there for years.
Is there any way to get rid of it? I´m checking it right now.


Iron contamination often occurs in low quality HCl like you find in hardware store "muriatic acid." It would have come with the stuff that you bought and not been introduced afterward.
Despite that, some brands are actually quite pure. When I started rounding up chemicals from around the house, I found a gallon of SMART brand 31.45% muriatic acid in my garage that had been there for about ten years. It is almost completely clear. You have to try really hard to imagine that it has the slightest yellow tint. I noticed at Home Depot the other day that they still sell that exact brand, and it comes in clear plastic jugs so you can actually see that it's colorless.

Also, if you're still not sure if what you have is HCl, carefully give it a smell. If you are treated to a strong odor of chlorine/vinegar-from-hell then it is HCl.

HgDinis25 - 18-4-2014 at 11:45

Quote: Originally posted by Burner  
Quote: Originally posted by sasan  
Hgdinis 25 it was made of poly ethylene I think
I'm wondering too why the bottle got inflexible,as a matter of fact,before I place the HCl in it,there was rhodium sulfate and dilute sulfuric in the bottle


I am guessing that the bottle might have been LDPE and may have had extensive sunlight exposure. I have seen that happen before, though it should not occur.


Agree. Most low quality plastics like PET, PE, LDPE etc. will get weaker over time, if not stored in the right conditions. Too much heat, too much cold, too much sun light, all this makes the plastic weaker.

Also, plastics that suffer aging tend to shatter...