A solution of ions and a solution of ions are each mixed with in separate beakers at

CHEMISTRY · Single correct · AP · Chemistry · Equilibrium · Equilibrium

Problem

0.010\,\text{M}

solution of

Ba^{2+}

ions and a

0.010\,\text{M}

solution of

Ag^{+}

ions are each mixed with

Na_2SO_4\,(aq)

in separate beakers at

25\,^\circ\text{C}

. The relevant solubility product constants are

K_{sp}(\mathrm{BaSO_4}) = 1.1\times10^{-10}

and

K_{sp}(\mathrm{Ag_2SO_4}) = 1.2\times10^{-5}

. Which statement best predicts which solid will precipitate first as sulfate ions are gradually added? (a)

\mathrm{Ag_2SO_4}

will precipitate before

\mathrm{BaSO_4}

because its

K_{sp}

value is larger. (b) Both sulfates will begin to precipitate at the same sulfate concentration since the two solutions have identical

0.010\,\text{M}

cation concentrations. (c)

\mathrm{BaSO_4}

will precipitate before

\mathrm{Ag_2SO_4}

because it requires a much lower

[\mathrm{SO_4^{2-}}]

to exceed

K_{sp}

. (d) No precipitate will form in either beaker because the sulfate concentration can never become great enough to surpass either

K_{sp}

value.