[Goala]

Would 2-Butyn-1-ol be found in the aqueous or organic layer of an extraction?

I would guess aqeous because there is an alcohol functional group, but I am not 100% sure. Any help would be appreciated! Thanks!

[discodermolide]

I would think it will be in the organic layer.
Having an OH group does not mean that it will dissolve in water, there is the rest of the molecule to consider.

[benjamin5476]

I would think it will be in the organic layer.
Having an OH group does not mean that it will dissolve in water, there is the rest of the molecule to consider.

I think that too,The extraction effect depends on your choice of what organic phase is .

[Goala]

I would think it will be in the organic layer.
Having an OH group does not mean that it will dissolve in water, there is the rest of the molecule to consider.

Really an OH group does not mean that it will dissolve in water? How about if I ahd phenol then? Would I extract it in an organic or aqueous layer?

What is the rule then regarding if my product will be in the aqueous or organic layer?

I guess maybe a good solvent to extract my 2-butyn-1-ol would be THF, no?

[discodermolide]

The presence of an OH group does not mean that it is water soluble.
Phenol will not dissolve in water to any great extent, I think is around 8%.
The rule about organic solubility does not exist it depends upon the solvent you are using and the compound you are trying to dissolve, like dissolves like!
THF is water miscible therefore it is not a good solvent to use.
Use toluene, or dichloromethane to extract your compound, probably dichloromethane is the best.

[Goala]

Thank you discodermolide.

Can you give me four compounds then that are miscible in an aqueous solvent please just as an example then.

[discodermolide]

methanol
ethanol
tetrahydrofuran
acetone
acetic acid
acetonitrile
dimethyl sulfoxide
dimethyl formamide
gylcerol
pyridine

That will do.

[Goala]

Thank you kind sir!

So all hydrocarbons are only miscible in the organic layer except if they have a carboxylic acid moiety like acetic acid.

[discodermolide]

Sorry, I'm not sure I know what you mean. Please elaborate.

[Goala]

Ok, so let's take three compounds: Hexane, Hexanol, and Hexanoic acid.

Hexane and Hexanol would be extracted from an organic solvent while hexanoic acid would be extracted from an aqueous solvent like water.

[discodermolide]

Ok, so let's take three compounds: Hexane, Hexanol, and Hexanoic acid.

Hexane and Hexanol would be extracted from an organic solvent while hexanoic acid would be extracted from an aqueous solvent like water.

I still don't understand what you mean.
Hexane, hexanol are not water miscible. Hexanoic acid has a water solubility of 1%.
An extraction is usually carried out between two immiscible solvents, in order to remove something from one of them.
For example, you have done a reaction, to start to purify the desired product you may begin by doing an extraction of the reaction mixture by dissolving the reaction mixture in a water immiscible solvent then add water. All the water soluble impurities go into the water phase and hopefully after phase separation and removal of the organic solvent you have a pure product.
Have a look here  http://www.youtube.com/watch?v=cMrWdx1KdU8

[Goala]

methanol
ethanol
tetrahydrofuran
acetone
acetic acid
acetonitrile
dimethyl sulfoxide
dimethyl formamide
gylcerol
pyridine

That will do.

Ok, well you said up above here that the compounds you listed are miscible in an aqueous solvent. Isn't water an aqueous solvent?

So why does hexanoic acid only have a 1% water solubility while acetic acid is miscible in water?

[discodermolide]

Of course water is an aqueous solvent. Don't ask why I wrote that

Because of the 6 carbon chain, it is very lipophillic. Make it's sodium salt then the solubility would go up.

[fledarmus]

The larger the hydrocarbon group attached to a typically water soluble functional group, the less water soluble it will be. For example, alcohols - -OH groups lead to water solubility, and methanol, ethanol, and propanols are miscible in water. The butanols and pentanols are less water soluble, and by the time you get to octanol, it is totally insoluble.

The measure you are looking for is the partition coefficient - this is a measurement of the compound's relative solubility in water and in octanol. It is usually reported as logP. If logP = 1, then the compound will be equally dissolved in water and octanol, >1 is more in the octanol (hydrophobic), and <1 is more in the water (hydrophilic).

The solubility changes with pH because the functional groups change with pH. In your phenol example - phenol can easily be extracted from water, but if you raise the pH, the phenol is deprotonated and becomes much more water soluble. You can extract phenol from an organic solvent using dilute sodium carbonate, and back-extract it into an organic solvent by acidifying the aqueous solution. The same for carboxylic acids - hexanoic acid isn't soluble in water, but it is soluble in a dilute aqueous base. Amines go the other direction - larger amines are not soluble in water, but are soluble in dilute aqueous acids. You can control which layer these types of molecules go to by controlling the pH of the aqueous layer.

I hope some of this helps.

[Goala]

The larger the hydrocarbon group attached to a typically water soluble functional group, the less water soluble it will be. For example, alcohols - -OH groups lead to water solubility, and methanol, ethanol, and propanols are miscible in water. The butanols and pentanols are less water soluble, and by the time you get to octanol, it is totally insoluble.

The measure you are looking for is the partition coefficient - this is a measurement of the compound's relative solubility in water and in octanol. It is usually reported as logP. If logP = 1, then the compound will be equally dissolved in water and octanol, >1 is more in the octanol (hydrophobic), and <1 is more in the water (hydrophilic).

The solubility changes with pH because the functional groups change with pH. In your phenol example - phenol can easily be extracted from water, but if you raise the pH, the phenol is deprotonated and becomes much more water soluble. You can extract phenol from an organic solvent using dilute sodium carbonate, and back-extract it into an organic solvent by acidifying the aqueous solution. The same for carboxylic acids - hexanoic acid isn't soluble in water, but it is soluble in a dilute aqueous base. Amines go the other direction - larger amines are not soluble in water, but are soluble in dilute aqueous acids. You can control which layer these types of molecules go to by controlling the pH of the aqueous layer.

I hope some of this helps.

Brilliant! You get a mole snack!