Answer
The strongest acid has the weakest conjugate base while the weakest acid has the strongest conjugate base. Also, remember that the more stable a base is, the weaker it is.
Work Step by Step
The answer to part b is in order of decreasing stability of conjugate bases, which also means it is in order of increasing basicity. Their conjugate acids are therefore in the order of decreasing acidity (which is the answer to this part). Simply take the answer from part b and add H+ to each base. Keep the order of the compounds.
