steph du - 2020-01-10
Thank you for your incredibly interesting reups, dude!
You've made my entire week!
I remember a large jar of bright yellow Picric acid in our histopathology lab. It was always kept moist. it was used to make Van Gieson's stain. Was told it must never be allowed to dry out.
Respect for keeping these vids available. You got a subscription from me!
One of my favorite things about picric acid is its incendiary effect
Thank you for uploading, I'm synthesizing this in my online laboratory tomorrow :D
I'm doing it right now, but with a different method.
Thanks for uploading man
Have you used this acid for anything yet?
Thanks dude, shame youtube got so damn lame...
thanks!
Thanks. 😁
Cool
A ship full of Picric acid is what caused the Halifax explosion.
It was a cocktail of bad shit. She was loaded to the tits with Benzol, TNT and Guncotton in addition to the Picric Acid.
Yooooooooooo
hey!
lacrthxx14 - 2020-03-31
This is one of the few procedures of nile red that I think that are wrong... The addition sulphonation must be carried out in a molar ratio of 3:1 sulfuric acid/phenol and for 5 hours at 100° at least and the addition of the nitric acid must be done DROPWISE to prevent that degradation that will just oxidize the phenol to oxalic acid... That's why he obtained that poor yield... I have done this experiment and it requires a little expertice when it comes to the nitration.
Pavel Ř. - 2020-06-02
Hi, how big was your yield? I've done this synthesis with a friend, but we've used 25g of phenol (0,266mol) and only 33ml of 96% H2SO4 (0,59mol) and we've carried out sulphonation in a hot water bath for only ~1h. We then added 80ml of conc. nitric acid dropwise while cooling in an ice bath. The yield was 52% of nicely pure yellow crystals. I would like to know, if there's any bigger difference between in yield...? 5 hours seems like unnecessary overkill to me.
lacrthxx14 - 2020-06-02
@Pavel Ř. I also obtained a similar yield (after recrystallization) as you with 5 hours of sulfonation so, despite of some papers calling for at least 5 hours, also just an hour may be sufficient.
Pavel Ř. - 2020-06-03
@lacrthxx14 Okay, thank you. As you said, it means it's probably enough. I've read that even 30mins should be sufficient, but we did 1h to be sure. I think they often use excess of time and reagents in serious papers just to be sure...
Senvr - 2021-12-21
might be why he removed it
Jack McLane - 2022-01-24
Nitrations are almost always better done dropwise.