In: Chemistry
Identify organic and aqueous solvent layers AND Isolate and ID organic compound
Possible solids: fluorene, triphenylmethanol, benzoic acid, salicylic acid, ethyl-4-aminobenzoate, para-aminoacetophenone
Possible organic solvents: diethyl ether, hexane, methylene chloride
Possible aqueous layer: water, 1M NaOH, or 1M HCl
What steps can be done to do this in the lab?
You can begin by adding a little volume of hexane, the only compound that will dissolve is fluorene (the least polar compound). To the residual compounds you can add diethyl ether and all should dissolve, then add a volume of 1M NaOH, the acid compounds will be deprotonated and will dissolve into the aqueous layer and can be extracted, this are benzoic acid and the salicylic acid; to separate them you need to add 1M NaOH to obtain a neutral pH, the compounds will protonate again, and you can add ether, salicylic acid should be slightly more soluble in water than the other acid due to the presence of -OH group, benzoic acid should remain the the organic phase,note that for a good separation you need to use another technique because both acids have similar polarity.
The remaining compounds (in the initial ether phase) can be extracted adding 1M HCl, the compounds with the -NH2 group will protonate and dissolve into the aqueous phase (ethyl-4-aminobenzoate and para-aminoacetophenone), triphenylmethanol should reamain the the ether phase. The extracted aqueous phase with ethyl-4-aminobenzoate and para-aminoacetophenone can be treated with 1M NaOH to get a neutral pH and then with a volume of ether, ethyl-4-aminobenzoate will be slightly more soluble in this organic phase because an ether is les spolar than an esther, but again,both have similar polarity and the separation will not be very effective, there's necessary an additional separation technique.