Answer :
Considering the Ksp values provided for the given salts, the goal is to find a solution that would produce the least amount of precipitate when used instead of K2CO3(aq) in the precipitation procedure.
To determine which solution would produce the least number of moles of precipitate, we need to look at the common ions formed by each salt when dissolved in water.
Let's analyze the options:
(A) 0.200 M NaNO3(aq) - This solution will produce NO3- ions, which are not common ions with K2CO3. It is not likely to produce a precipitate.
(B) 0.200 M NaF(aq) - This solution will produce F- ions, which are also not common ions with K2CO3. It is unlikely to produce a precipitate.
(C) 0.100 M Na2SO4(aq) - This solution will produce SO4^2- ions, which can form a precipitate with some cations, but not with the cations from K2CO3. So, it may not produce a significant amount of precipitate.
(D) 0.100 M Na2CrO4(aq) - This solution will produce CrO4^2- ions, which can form a precipitate with some cations, but not with the cations from K2CO3. Therefore, it may not produce a substantial amount of precipitate.
Among the options provided, (A) 0.200 M NaNO3(aq) and (B) 0.200 M NaF(aq) are likely to produce the least amount of precipitate since they do not share common ions with K2CO3 and are less likely to form a precipitate in this context.
