[chem] solubility 問題 (organic chem)

Question

why is butan-1-ol more soluble in conc. HCl than in water?


why is phenol more soluble in NaOH than in water?

Answer 1

Yep, the poster above me is correct about the 2nd question. It's because NaOH deprotonates the OH group of phenol, giving the anion that is extremely water soluble - in terms of organis extractions with aqueous NaOH.
1st question: Because HCl becomes H+ and Cl- in aqueous solutions. The H+ can protonate the OH group of butanol, giving the cation ion the pervious poster mentioned. Generally, whatever that carries either a +ve or -ve charge WILL be water soluble - now this is again, in terms of organic extractions with AQUEOUS solutions and NOT water! That said, butanol is still water soluble but because H2O cannot become ions like HCl, then it's ability to bind to an oxygen to make it "water soluble" is greatly reduced. That's why butanol is more soluble in HCl than water.
Hope that makes sense

Answer 2

I am not very sure about the first question. It may be due to the formation of

CH3CH2CH2CH2OH2+

one proton H+ is added to the oxygen of the hydroxyl group. ( protonated )
the ion so formed is easily soluble in the polar solvent ( water )

I am very sure about the next question. It is due to the formation of phenoxide ion in the strong alkaline solution. the phenoxide ion is formed from lose of a proton H+ from the hydroxyl group. C6H5O-. the OH- of NaOH help to pull out the proton from hydroxyl group.