LifeisElemental
Harmless
Posts: 39
Registered: 18-7-2014
Location: United States
Member Is Offline
|
|
Iodoform (Haloform Reaction) Complete Video
Hi guys! You may remember that awhile back I had posted a really silly skit on lead (II) iodide. There was a lot of good feedback there and from that
I created the first episode in what I hope to become series of videos on chemistry.
I am really excited to hear your feedback on this first episode of the series. Do you like the structure - is there anything you might like changed?
Most of all does anyone have any suggestions for some visually-stunning reactions that I should cover?
CiC - Iodoform Synthesis (Haloform Reaction) [YOUTUBE LINK]
Thanks guys!
|
|
|
Justin Blaise
Hazard to Self
Posts: 82
Registered: 5-10-2011
Location: Parts Unknown
Member Is Offline
Mood: No Mood
|
|
I definitely like the video. I have a few comments about the mechanism. First, you're missing the arrow that shows the iodine-iodine bond breaking.
Second, when you get to your tetrahedral intermediate, you show triiodide as your leaving group instead of the -CI3 moiety. Nice video though. For a
pretty nice visual, you could do one of the clock reactions. Lots of interesting chemistry there.
|
|
|
LifeisElemental
Harmless
Posts: 39
Registered: 18-7-2014
Location: United States
Member Is Offline
|
|
Quote: Originally posted by Justin Blaise  | | I definitely like the video. I have a few comments about the mechanism. First, you're missing the arrow that shows the iodine-iodine bond breaking.
Second, when you get to your tetrahedral intermediate, you show triiodide as your leaving group instead of the -CI3 moiety. Nice video though. For a
pretty nice visual, you could do one of the clock reactions. Lots of interesting chemistry there. |
Good idea on the clock reactions! I tried to correct those errors by annotations - noticed by of those after post unfortunately!
I was told this was a poor crystallization could anyone elaborate on why? I don't doubt it but feedback would help for next time.
|
|
|
chemrox
International Hazard
Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline
Mood: LaGrangian
|
|
You didn't talk about tautomerism. I know that "plastic music" is popular on youtubes but it's not very professional and contrasted sharply with the
other aspects of your presentation which were very good. I found the pace a little hyper and I think your crystallization could be more crisp. I'd run
through it a few more times, playing with stoichiometry and temperature and see if I couldn't get a more uniform, snappier precipitation. It's worth
working on a bit more. Thanks for asking. BTW I don't know where the comment page goes when I try to comment online. After you perfect it you may want
some approbation from here. Please consider changing the music or leaving it altogether; in any case slow down the pace a bit so I don't feel like I
might be missing steps. Check your arrows and bring up keto enol tautomerism whatever the equilibrium is doing.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
|
|
|
Justin Blaise
Hazard to Self
Posts: 82
Registered: 5-10-2011
Location: Parts Unknown
Member Is Offline
Mood: No Mood
|
|
It looks like after you let the solution cool and form crystals you also add some anti-solvent (water?) to precipitate the rest of the product. If
this is what you did, then that is a poor recrystallization. The anti-solvent just reprecipitates any impurities you remove by crystallization. If you
had instead just filtered and washed the initial crystals, then that would be a proper recrystallization. That may be what you received criticism
for. Then again, I'm not sure exactly what you did, so I may be off base. If so, please post what you did exactly and I can give it another go.
Again though, I did like the video and it seems like you have a pretty solid grasp on the chemistry and safety aspects which is refreshing to see on
YouTube.
|
|
|
LifeisElemental
Harmless
Posts: 39
Registered: 18-7-2014
Location: United States
Member Is Offline
|
|
| Quote: Originally posted by Justin Blaise | It looks like after you let the solution cool and form crystals you also add some anti-solvent (water?) to precipitate the rest of the product. If
this is what you did, then that is a poor recrystallization. The anti-solvent just reprecipitates any impurities you remove by crystallization. If you
had instead just filtered and washed the initial crystals, then that would be a proper recrystallization. That may be what you received criticism
for. Then again, I'm not sure exactly what you did, so I may be off base. If so, please post what you did exactly and I can give it another go.
Again though, I did like the video and it seems like you have a pretty solid grasp on the chemistry and safety aspects which is refreshing to see on
YouTube. |
That was it! I added D.I. water. Thanks for pointing that out - I saw it mentioned online to do that and didn't think much of it. I will add an
annotation to make a note of this and be careful of this in the future.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
