Sciencemadness Discussion Board

Very large needles in my H2SO4/KNO3 mix?

gnitseretni - 3-12-2007 at 14:45

hi folks,

ok here's the deal.. i wanted to make some HNO3 the brainfever way but instead of heating it, I wanted to try and do it without heating it and just let it stand for a few days or however long it takes to get some HNO3.

I set it all up a little before noon. I just came back from work (about 5 hours after I set it up) and had a look at it.. no HNO3 yet, but what I did see were some large and I'm talking anywhere in between 1/2" to 1" in length colorless needles in my H2SO4/KNO3 mixture.

What could it be? Has to be potassium sulphate, right? I wish I could take a pic but i got no camera. It actually looks pretty cool, but it's just not part of the plan.

The brand drain cleaner I used is called Marc 55 heavy duty drain cleaner. The KNO3 is stump remover from the walmart, in case those details help any. I never used this drain cleaner before by the way and I don't know what's in it as I can't find a MSDS for it. It's not colorless but it's a lot clearer than the Liquid Fire brand that I usually use, which has never given me any trouble so far.

So, probably potassium sulphate, right?

12AX7 - 3-12-2007 at 16:02

In the acid mix, it would be KHSO4.

Hmm, KHSO4 gives me octahedral (or at least truncated cubic or anticubic) crystals.

If nothing else, seperate it, wash with cold water, dissolve in more and evaporate and recrystallize. See if it goes to a different habit.

Tim

not_important - 3-12-2007 at 16:14

Quote:
MARC 55 HEAVY DUTY DRAIN CLEANER AND SEWER AID
Contains specially inhibited concentrated sulfuric acid.


Without the MSDS or other ingredients listing who knows. Could be as you suggest, could be thiotimoline, or axonite, or Fulgarator-Deflagrator.

zeppelin69 - 3-12-2007 at 16:55

The potassium bisulfate left over from my nitric distillations are always needle like. I too use potassium nitrate from stump remover, and drain opener with inhibitors.

guy - 4-12-2007 at 23:21

KNO3 is needle shaped. You probably dissolved a large amount of KNO3 when the solution was hot from adding H2SO4. It later crystallized out.

KHSO4 and K2SO4 are not needly to my knowledge.