Rank the following bases in order of relative strength, from weakest to strongest: formate ion, cyanide ion, and acetate ion.
Strategy

This problem can be solved without calculations, because Table 15.6 lists values of K_a for each acid. The acids can be ranked in order of K_a, and the conjugate bases will be in the opposite order, because the stronger an acid, the weaker its conjugate base.

Table 15.6