Organic Chemistry Problem. I need help please!?

Question

Suggest a reason why 2-methyl-1-propanol is more soluble in water than 1-butanol.
Does it have to do with hydrogen bonding?

Answer 1

In the same way that 2-methyl-1-propanol would have a higher boiling point than 1-butanol. The substitution lowers the effective surface area of the alcohol in 2-methyl-1-propanol, allowing for more hydrogen bonding interactions between the alcohol groups.

Answer 2

hmm, this is quite tricky,

you're right about hydrogen bonding, interaction with OH groups is usually the most important thing affecting solubility, however in these 2 molecules are very similar, in fact they're isomers and the only difference is that one is branched and the other is a linear chain. The branching isnt going to have a massive effect on the electronics of the hydroxyl group, but i think that the branched molecule will be more acidic because it could conceivably form a tertiary carbocation at the 2-position. If thats the case then you could think of the lone hydrogen at the 2 position being more ∂-ve and the remaining molecule being more ∂+ve, a dipole! because of this extra polarity that you dont get in the butyl counterpart, the 2-methyl-1-propanol will be more soluble in water. Its a theory anyway!

hope this helps