Help identify acid

[g_axelsson]

Some other simple tests for acids...

A drop of sulfuric acid into lead chloride solution precipitates lead sulfate. Only concentrated acid sputters and can be hard to see in just a few drops if you haven't seen it before.
Concentrated sulfuric is oily and very heavy.

A piece of silver will dissolve in nitric acid without any silver chloride formed. The formed silver nitrate can be used to detect chloride containing solutions, like hydrochloric acid.

A piece of copper will dissolve in nitric acid, but hydrochloric and sulfuric acid will just clean the surface from oxides, making it brighter.

If the bottles are clear, put it in the sun and in an hour you can see a pale brown-red gas above any nitric acid. That's NOx that is formed from the acid breaking down.

As pieces of copper or silver, use a wire that is easily just dipped ad the end to see the reaction and can easily be pulled up, cleaned and wiped off to do more testing.

Göran

 

[upcyclist]

Thanks, guys.

A piece of silver will dissolve in nitric acid without any silver chloride formed. The formed silver nitrate can be used to detect chloride containing solutions, like hydrochloric acid.

...

As pieces of copper or silver, use a wire that is easily just dipped ad the end to see the reaction and can easily be pulled up, cleaned and wiped off to do more testing.

Göran--the silver nitrate test is handy, but first I need to find a local NOx supplier that'll sell me something as small as a liter or half-liter to start out with, hehe (no point in buying gallons until I know for sure what quantities I'll use). Once I do, would a 100mg silver per 100ml solution ("standard solution") suffice? May as well kill two birds with one stone if I can!

The second bit about wire will be easy enough--as a silversmith & chainmailleur, I've got plenty of wire

--Eric

 

[Eamonn]

I hope its not Hydroflouric acid(HF). I dont know a simple test for HF.
If its in a glass container its not HF as HF eats glass.
You don't want this stuff around if you can help it.
A drop on your skin will cause a nasty burn and dammage to your bones.

 

[upcyclist]

Agreed--HF is evil stuff. Luckily, there's almost no reason for an electroplater to use it. To my knowledge, no one has ever done glass/enamel etching in that building. In jewelry/crafting circles at least, no one ever messes with HF unless they specifically need to eat glass. There's lots of cheaper and safer acids to choose from.

But yes, any unidentified low-pH stuff could be HF. Not likely, but possible.

 

[g_axelsson]

The silver nitrate with hydrochloric acid reaction is very easily seen, any concentration works but when the concentration goes down it can be hard to see.

Göran