DoctaWalnuts
06-10-2009, 04:57 PM
I have the 2008 Destroyer this is number 151 in Ochem..
If NaHCO3 was added, which compound would be in the aqueous layer?
a. Sodium benzoate
b. toulene
c. Sodium bicarbonate
d. Sodium phenoxide
e. anilline
Answer is A. But why wouldn't the phenoxide be in the aqueous layer as well?
Thank you!
nze82
06-10-2009, 05:12 PM
I have the 2008 Destroyer this is number 151 in Ochem..
If NaHCO3 was added, which compound would be in the aqueous layer?
a. Sodium benzoate
b. toulene
c. Sodium bicarbonate
d. Sodium phenoxide
e. anilline
Answer is A. But why wouldn't the phenoxide be in the aqueous layer as well?
Thank you!
I'm guessing since the Benzoate component of compound A is more polar than the Phenoxide component of compound B, it can compensate for the large carbon ring (The major hydrophobic portion of the compound) much better and therefore, facilitate the compound to dissolve in the aqueous layer to a greater extent.
DoctaWalnuts
06-10-2009, 05:17 PM
Thank you for your response. I see what you are saying..but I don't think that would be intuitive for me at least. I guess I'm mainly focusing on the ability to hydrogen bond and thus would be in the aqueous layer.
Aniline would also be in the aqeous layer though because aniline the Nitrogen can H-bond..err....
pbure9
06-10-2009, 06:23 PM
This is a lab type question and a good one I think. Benzoic acid is a much stronger ACID than phenol therefore only requires a weaker base to react with it. Phenol would need to react with a strong base to be deprotonated, something like KOH/NaOH.
And aniline is basic, so if we add HCl or acid, we'd find its ion in the aqueous solution.
DoctaWalnuts
06-10-2009, 07:04 PM
This is a lab type question and a good one I think. Benzoic acid is a much stronger base than phenol therefore only requires a weaker base to react with it. Phenol would need to react with a strong base to be deprotonated, something like KOH/NaOH.
And aniline is basic, so if we add HCl or acid, we'd find its ion in the aqueous solution.
Ohhh good points!! Both aniline and phenol are basic. The OH group donates electrons to the ring just as the NH2 group does in phenol. Right?
But the Benzoic acid (before addition of the base)http://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Sodium-benzoate-skeletal.png/100px-Sodium-benzoate-skeletal.png (http://en.wikipedia.org/wiki/File:Sodium-benzoate-skeletal.png)
was acidic because of the electron withdrawing group (COOH) right?
In that case, the aniline and phenol would require an acid! While the Benzoic acid would require a BASE!! Yay!! :D
GiTsticker
06-10-2009, 07:23 PM
... Benzoic acid is a much stronger base than phenol...
I think he meant stronger acid. Indeed it is the strongest acid of the bunch and thus the most likely to be deprotonated by HCO3- thus leaving it with a negative charge which makes it much more polar.
In that case, the aniline and phenol would require an acid
I think aniline would need an acid to protonate the N and leave it with a positive charge and phenol would need a strong base to deprotonate the O and leave it with a negative charge.
DoctaWalnuts
06-10-2009, 07:33 PM
yeah phenol isn't a base, it's an acid. But aniline isn't a base either. It's more basic than carboxylic acid, but it's not a base. Right..I get what he's saying though. It's a stronger acid so it can work with a weaker base.
The phenol and aniline are both weaker acids and would require stronger bases like NaOH or NaNH2. Thank you guys!
pbure9
06-10-2009, 08:07 PM
I think he meant stronger acid. Indeed it is the strongest acid of the bunch and thus the most likely to be deprotonated by HCO3- thus leaving it with a negative charge which makes it much more polar.
I think aniline would need an acid to protonate the N and leave it with a positive charge and phenol would need a strong base to deprotonate the O and leave it with a negative charge.
woops i did mean acid lol. changed that.
and id say aniline is pretty basic as GiT said. It would need a proton thats why it would be reactive in acid not base.