At 25 °C the following values are reported: AgBr: PbBr : Which statement about…

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

Problem

At 25 °C the following values are reported: AgBr:

K_{sp}=5.0\times10^{-13}

PbBr

_2

K_{sp}=6.6\times10^{-6}

Which statement about saturated aqueous solutions of these salts is most accurate? (a) Because both salts contain Br

^{-}

, their molar solubilities in pure water must be identical. (b) PbBr

_2

has the greater molar solubility because its larger

K_{sp}

value and dissociation into three ions allow more solid to dissolve. (c) The

+2

charge on Pb

^{2+}

makes the ionic lattice harder to separate, so PbBr

_2

is less soluble than AgBr. (d) Since the salts have different stoichiometries, their

K_{sp}

values cannot be compared, and no prediction about relative solubilities can be made.