I have learned an important lesson today, and I am shocked at my own ignorance. I was synthesizing salycilic acid from ASA, and made the mistake of
using a small flask. After all of the ASA was disolved in the water and the solution was smoothly refluxing, I noticed some undisolved impurities.
Approximately 10 minutes later, the flasked bumped hard, shooting hot solution of SA and acetic acid all over my porch. I was not around when this
happened, luckily, but would like this to be a lesson to beginners. Use the correct sized flask, dont push it!
EDIT: I feel that I should add that I knew what I was doing and was too lazy to use a larger flask as it was in use, and that I still got a decent
yeild.
[Edited on 11-11-18 by Abromination]
[Edited on 11-11-18 by Abromination]CharlieA - 10-11-2018 at 16:58
Well said...also, don't leave something being heated. I learned this the hard way on my first industrial job and blew a years pay worth of product.
And believe it or not, I wasn't fired on the spot!j_sum1 - 10-11-2018 at 17:29
This is a good thread idea. With experience we do a lot of things correctly without really thinking. Without experience we kind of bumble along and
occasionally have some close calls. Let me add a couple of important lessons of my own.
1. Heating a closed system
Don't do it. Of course I had heard that. But on first getting my first distillation set I was diligent to connect everything properly as it seemed to
be designed. I wasn't pulling a vacuum so did not use a vacuum take off adapter. Lots of grease on every joint. Keck clips on everything. (Well,
nearly everything, fortunately). A couple of minutes in and my thermometer adapter and thermometer hit the ceiling.
2. Know exactly what your reaction is as well as side reactions and side products.
Processing some battery gunk, and having a shortage of H2SO4, I decided to go for MnCl2 instead and so used HCl which was readily available for me.
20g of battery paste and I had copious foaming and vile green gas eminating from the flask. That was a case of holding breath, evacuating, and coming
back a few hours later to clean up the mess. By that time I had done some calculations and knew what I had done and how much chlorine I had created.
That calculation would have been much better done beforehand. But I wasn't even thinking of MnO2 as an oxidant.
3. Bumping is a thing. And concentrated H2SO4 bumps quite well.
Boiling down some sulfuric acid that I made by electrolysis. My favourite 1L beaker on the hot plate. I was proceeding cautiously and did have boiling
chips. (Actually, crushed glass does not make for great boiling chips but I did not knoe that then.) The beaker launched itself right off the bench
and smashed on the floor; splashing 50mL of hot 70% sulfuric acid everywhere including my legs.
I am not sure which upset me the most: the close call and my stupidity, breaking my newly-acquired glassware, or losing several days of electrolysis.
The concrete floor was pretty clean after that event.
4. General rule: if uncertain, do it at small scale.
No one event, but this has been a great habit to acquire. I can think of a number of interesting experiments that would have been disastrous at large
scale - including unintentional production of chloramines.
[Edited on 11-11-2018 by j_sum1]XeonTheMGPony - 11-11-2018 at 06:12
Well said...also, don't leave something being heated. I learned this the hard way on my first industrial job and blew a years pay worth of product.
And believe it or not, I wasn't fired on the spot!
Your lucky to have a reasonable Employer, accidents happen, I am getting annoyed with this false belief by an over coddled society that thinks nothing
bad should ever happen. So such places are becoming rare.
Be diligent in your study of the job, learn all procedures and protocols even if not directly related to you, and soon you will be managing the crew!
and learn the ins and outs of the process.DavidJR - 11-11-2018 at 07:55
Well said...also, don't leave something being heated. I learned this the hard way on my first industrial job and blew a years pay worth of product.
And believe it or not, I wasn't fired on the spot!
Why on earth would they fire you right after they invested so much money on effective training?Ubya - 11-11-2018 at 11:23
Never leave something heating unattended, my first and last time i did it i was evaporating a solution of copper sulphate made electrolyzing copper
metal in a sulphuric acid solution.
i used my kitchen stove (didn't have a hotplate at the time), i had the flame on really low because the solution would easily bump otherwise, it took
a few hours to boil just 200ml so i got really bored. i made sure that the flame was low enough to not make any bumping, and went to my bedroom. i
totally forgot what i was doing and after a while i started smelling a strange odour, suddendly i remembered the beaker on the stove, i rushed in my
kitchen, (there was excess sulphuric acid in solution so after all the water evaporated the acid started to boil, filling the whole house of acid
vapour) i opened the door and every window, i used a big sheet of plywood to fan the acid away while taking breaths out of the window but i could not
avoid to inhale some of the acid/air mix so my lungs started to hurt really bad, not a pleasant experience.
now i babysit even water boiling, if have to leave (to take a shit for example hahah) i use my spare phone as a remote camera to monitor everything
