In the Lewis definition, bases are electron-pair donors. t-butyl alcohol has the most electron-donating R groups and makes it the strongest electron pair donor, hence strongest base.
edit* and t-butyl is apparently the least acidic for the same reason above.
Such questions are poorly written, but to make it worse, the matter is somewhat complicated....
In the gaseous phase, tert-butanol is the MOST acidic. The methyl groups act to inductively stabilize the negative charge of the cojugate base, the alkoxide....
Polarizability of alkyl substituents for purposes of inductive stability can work to stabilize EITHER positive or negative charges.
CH3-....imagine the methyl as a circular electron cloud. The bond extending from the methyl group is closest to either a positive or negative formal charge. The electron cloud of the methyl can polarize itself to generate a partial positive charge one side and a partial negative charge on the other (whichever way stabilizes the formal charge) to provide inductive stability.
Thus, in the case of alcohol conjugate bases, alkyl polarizability stabilizes a negative charge. In the case of carbocations, alkyl polarizability stabilizes a positive charge.
However, that's only part of the answer.....
In AQUEOUS SOLUTION, conjugate base (alkoxide) stability is also provided by solvation. Empirically, we see that solvation plays a greater role in conjugate base stabiity and for this reason primary alcohols are most acidic in aqueous solution.
*notice that inductive stability from alkyl substituent polarizability and stability from solvation oppose one another*...
The question of alcohol
acidity somewhat easier than answering the question of alcohols
basicity....
To answer the question we have to determine the relative stability of the R-OH2 + species....again we have opposing effects that play a role in cojugate acid stability; it would help if the problem specified the phase.
The achiever solution is incorrect because the carbocation formation step is irrelevant. Yes, the conjugate acid of tert-butanol will form the most stable carbocation, but that is irrelevant because the question of RELATIVE BASICITY is simply a matter of the relative EQUILIBRIUMS for the simple proton donation step.
Thus, it is a matter of determining the stability of ONLY the conjugate acids....R-OH2 + species..
