in the step of heating the Phthalic Anhydride and the Phenol with the acid, does it automaticly make Phenolphthalein, do you HAVE to make the solution straight away, or can you just let it dry and form a powder to store?
could you please explain how you obtained so much phthallic anhydride? I repeated nurdrage's process but ended up with half a gram instead of 13. I think I am doing something wrong but up until this point everything was going quite well.
@coolfacts123 After you placed the gloves in the alcohol and refluxed and decanted did you find the gloves turned "crispy" and hard? Did you use 91% alcohol? After NaOH did you get 2 layers? After HCL how much phthallic Acid did you get? Heating the phthallic Acid to convert it to anhydride is the hardest part. If you over heat.. it decomposes and a bunch of black junk forms on the bottom of the beaker. The trick is to watch it very closely start to form on the sides of the beaker.
An awesome video! It's nice to know how indicators are synthesized and a some background on the chemistry behind them rather than just accepting it as a mysteryious colour changing substance.
I'm trying to think...how is removing a proton from these oxygens causing the color change? I'm trying to explain it in terms of non degeneracy of the MO's of the oxygens, but my brain doesn't appear to be functioning atm...it's 330 am.
Very nice video. Quick question though. Alot of people(including myself) use Phenolpthalein to indicate when a acid titration is complete because of the basic solution. Since Phenolpthalein turns purple at about 8.2 pH, would this throw off the titration significantly because you have to keep adding your base past the point that all the acid is used up (neutral pH)? This has been bugging me for awhile, lol.
@PyroPortrayal Phenolpthalein is a pretty good ph indicator for strong acid-base titration. Why? Because the amount of base needed to turn your solution purple (thus 8.2pH) is very small and most of the times(that is depending on the situation) negligible. This is also proven by the pH/volume curves.
in the step of heating the Phthalic Anhydride and the Phenol with the acid, does it automaticly make Phenolphthalein, do you HAVE to make the solution straight away, or can you just let it dry and form a powder to store?
toothpick93 7 months ago
could you please explain how you obtained so much phthallic anhydride? I repeated nurdrage's process but ended up with half a gram instead of 13. I think I am doing something wrong but up until this point everything was going quite well.
coolfacts123 10 months ago
@coolfacts123 After you placed the gloves in the alcohol and refluxed and decanted did you find the gloves turned "crispy" and hard? Did you use 91% alcohol? After NaOH did you get 2 layers? After HCL how much phthallic Acid did you get? Heating the phthallic Acid to convert it to anhydride is the hardest part. If you over heat.. it decomposes and a bunch of black junk forms on the bottom of the beaker. The trick is to watch it very closely start to form on the sides of the beaker.
myst32YT 10 months ago
@coolfacts123 Also make sure the round bottom flask you use in the anhydride step has no ice in it.
myst32YT 10 months ago
You should try to isolate sucralose from Splenda. Basically you have to dissolve splenda in a solvent, filter the solution, and evaporae it.
HowToScience 10 months ago
Phthalic anhydride is also quite toxic...
douro20 10 months ago
An awesome video! It's nice to know how indicators are synthesized and a some background on the chemistry behind them rather than just accepting it as a mysteryious colour changing substance.
nodariel 10 months ago
excellent video.
quexalcoatl 10 months ago
@arborlab hahahaha that was my next video... Can't sneak anything by youtube users...
myst32YT 10 months ago
This is my favorite of your videos, Myst. Do you have a ScienceMadness account?
louforiginator 10 months ago
@louforiginator yes... it is myst32... but I never post...
myst32YT 10 months ago
wouldn't it be more soluble in ethanol?
MrLordBanana 10 months ago
@MrLordBanana Yes it is.. and you can use that instead if you like.
myst32YT 10 months ago
@MrLordBanana
Yes. Phenolphthalein is often prepared as a solution in alcohol.
douro20 10 months ago
I'm trying to think...how is removing a proton from these oxygens causing the color change? I'm trying to explain it in terms of non degeneracy of the MO's of the oxygens, but my brain doesn't appear to be functioning atm...it's 330 am.
zapo147 10 months ago
@zapo147 hmmm... I thought it had to do with conjugation...
myst32YT 10 months ago
Comment removed
zapo147 10 months ago
Very nice video. Quick question though. Alot of people(including myself) use Phenolpthalein to indicate when a acid titration is complete because of the basic solution. Since Phenolpthalein turns purple at about 8.2 pH, would this throw off the titration significantly because you have to keep adding your base past the point that all the acid is used up (neutral pH)? This has been bugging me for awhile, lol.
PyroPortrayal 10 months ago
@PyroPortrayal Phenolpthalein is a pretty good ph indicator for strong acid-base titration. Why? Because the amount of base needed to turn your solution purple (thus 8.2pH) is very small and most of the times(that is depending on the situation) negligible. This is also proven by the pH/volume curves.
deathnoteviewer 10 months ago
@deathnoteviewer
Ah, ok. Thank you for clarifying that. I like to titrate large amounts of acids anyway because I tend to get more accurate results that way.
PyroPortrayal 10 months ago