Armed Polite Society
September 21, 2020, 04:35:32 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: R.I.P. Scout26
 
   Home   Help Search Login Register  
Pages: [1]
  Print  
Author Topic: Look up the chemical formula before you clean something with sulfuric acid  (Read 68 times)
zxcvbob
friend
Senior Member
***
Posts: 9,667



« on: September 20, 2020, 07:34:44 PM »

I bought some sulfuric acid drain cleaner to clean an Erlenmeyer flask that had crud stuck to the bottom that I couldn't get off with anything else.  It did a pretty poor job at first (but it did kinda work), but then I heated it and it worked great.  That was a couple of weeks ago.

A plastic carboy that I used to ferment some beer had a white streak on the outside that I couldn't wash off.  I thought it was yeast from when the beer foamed out the top of the air lock, but I couldn't figure out why it was stuck so tight.  Tonight I decided to use the ol' H2SO4 on it.  The carboy is PET plastic, and that's acid resistant, right?   I used a Q-tip to apply the acid (the acid ate the cotton off the end right away but the stick part still worked) and it seemed to be working but awfully slowly.  I thought that was just cuz the acid was cold, but I couldn't use hot acid for this.  After it looked like it was all gone I washed the carboy with some water, and the whole area turned white.  I scrubbed it a bit and a lot of the white came off but it still looks like *expletive deleted*it.  Since it's on the outside and doesn't go very deep, it's still usable it just looks awful.  What happened?  (rhetorical)  PET doesn't contain any oxygen in the molecule for the acid to attack (along with 2 hydrogens), does it?  I looked it up. 



D'oh!   Face Palm!

I thought it was just huge chains of carbon and hydrogen, but that's polyethene (and polypropylene).

PS, the original streak was probably from sulfuric acid when I opened the bottle and spilled a drop w/o realizing it.  I opened it right there by where the fermenter was sitting.

PPS, sulfuric acid will etch the 420j2 stainless steel tip of your Buck knife when you use it to cut the plastic seal on the bottle.
Report to moderator   Logged

"It's good, though..."
kgbsquirrel
APS Photoshop God
friend
Senior Member
***
Posts: 3,960


Bill, slayer of threads.


« Reply #1 on: September 20, 2020, 08:25:05 PM »

Oops.
Report to moderator   Logged
Nick1911
Administrator
Senior Member
*****
Posts: 7,195



« Reply #2 on: September 20, 2020, 08:52:53 PM »

Ha, well now you know, and we know, so thanks for that.  smiley

Piranha solution is excellent for cleaning most organic crap off glassware, although finding hydrogen peroxide in a useful concentration can be a chore.
Report to moderator   Logged
zxcvbob
friend
Senior Member
***
Posts: 9,667



« Reply #3 on: September 20, 2020, 10:17:09 PM »

Ha, well now you know, and we know, so thanks for that.  smiley

Piranha solution is excellent for cleaning most organic crap off glassware, although finding hydrogen peroxide in a useful concentration can be a chore.

I'm aware of piranha solution, but can't find strong H2O2.  But 93% sulfuric acid works just fine when it's hot.  I think it becomes an oxidizer, plus pulling the water out of anything that has both hydrogen and oxygen in it.  Just let it cool completely before you dump it in the toilet  rolleyes
Report to moderator   Logged

"It's good, though..."
230RN
friend
Senior Member
***
Posts: 14,613


The avatar says it all.


« Reply #4 on: Today at 12:33:42 AM »

^And keep a bucket of water handy fir a quick-follow-up flush.

We used to use "chromic" acid, suphuric and potassium permanganate (an oxidizer, like H2O2) to clean burned-on organic crud.  I don't remember where the chrome came from, though. I always thought it was a misnomer or they were referring to something else by accident.

What I reallly wanted to add is that a way to scrub the insides of various glassware was to slosh some kitty litter around in it.

Yes, it would seem that con sulphuric will steal H and O in the form of water from just about anything. It is nasty stuff, as if I were telling you anything  new.

Keep that sodium bicarbonate handy,
Report to moderator   Logged

So far, President Trump has been either:

A.  The luckiest guy on the political scene...
B.  The guy with the clearest crytal ball...
C.  The most astute politiciam who ever lived...
D.  All of the above....
dogmush
friend
Senior Member
***
Posts: 8,670


« Reply #5 on: Today at 01:01:42 AM »

Ha, well now you know, and we know, so thanks for that.  smiley

Piranha solution is excellent for cleaning most organic crap off glassware, although finding hydrogen peroxide in a useful concentration can be a chore.

Walmart.

https://www.walmart.com/ip/H2O2-Liquid-Oxygen-34-Gallon/245174221
Report to moderator   Logged
Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!