Sciencemadness Discussion Board

Are Teflon corrosive-proof?

antimon - 24-6-2015 at 00:44

Hi, i have some 95% + pure HCl, 69 % HNO3, and other strong acids in Teflon bottles, and they have been there for about a year now, and i just wanted to ask you guys if i have a reason to worry about the acid corroding through the bottles any time soon?

I also have strong bases, like NaOH in the bottles they came in.

Thanks in advance.

Deathunter88 - 24-6-2015 at 01:14

If the acids and bases are in real Teflon bottles, there is absolutely no problem. Did the acids come in the Teflon bottles when you bought them? Real Teflon bottles are rather expensive so you need to double check if they are in fact in Teflon bottles.

Zyklon-A - 24-6-2015 at 01:57

Quote: Originally posted by antimon  
Hi, i have some 95% + pure HCl [...]

Really? Where can I acquire this unheard of acid, must be stored under very high pressures.
Azeotropic HCl (aq) is around 20% (at STP) however by bubbling anhydrous HCl (g) though (cold) water/dilute HCl (aq) 38% is achievable (at low temperatures).
This stuff (37-38%) is very useful, is some applications where minimizing the concentration of water is important.
Beware any concentrations of HCl in water will fume HCl gas/vapor. The higher the concentration the more it fumes. 20% e.g. is just an annoying experience, but over 35% could know you on the ground (personal experience).
Off topic, but just recently I inflated a large bollon with pure nitrogen gas, as I heard in can knock you out in seconds.
I sat down in a chair, opened the value in my mouth and it felt like I was just breathing air, as I continued breathing ,I felt dizzy, but somehow relaxed. Not sure what happened next, but I came to lying of my lab floor and 20 minutes had past.
Felt fine afterwards, minor headache that lasted less then 10 minutes is all, preshaps I was short of breathing for a couple hours as well.

MrHomeScientist - 24-6-2015 at 07:53

What did you think would happen? Nitrogen gas doesn't have any oxygen in it, you know. I hope you had someone nearby when you tried that 'experiment'.

aga - 24-6-2015 at 08:04

Quote: Originally posted by Zyklon-A  
over 35% could know you on the ground (personal experience).

In the Biblical sense ? Chemistry never ceases to amaze ...

Quote: Originally posted by Zyklon-A  
Not sure what happened next, but I came to lying of my lab floor and 20 minutes had past.

https://en.wikipedia.org/wiki/Nitrogen_narcosis

According to some, it is the most humane way to kill people.

Very silly and dangerous experiment to have done, yet hats off to you for having the balls (or insanity) to do so.

IrC - 24-6-2015 at 16:29

While this company is mainly concerned with O-rings, I think their Basic compatibility chart is the most complete I have found. From Acetaldehyde to Zirconium Nitrate with ratings from 1 to 4 (they are concerned with O-ring swelling), and Teflon is in the chart. At the least one can quickly determine whether a chemical is destructive to various materials which can be taken to be similar to containers made from these materials. Obviously other considerations like violent reactions between materials would have to be found elsewhere. In any case I have found this chart to be useful.

http://www.marcorubber.com/compatibility.htm

Also useful:

http://www.marcorubber.com/material_chart.htm

http://www.marcorubber.com/materialguide.htm

Dr.Bob - 25-6-2015 at 05:46

Teflon is NOT stable to strong base solutions... It is stable to almost all strong acids, but glass is still better for most acids, as it is less permeable to air, water, and other gases. Teflon is more permeable than glass to gases.

Bases will also slowly etch glass, so storing them in simple polypropylene or PE bottles is best.