## Chemistry (4th Edition)

(a) $9.1 \times 10^{-9}M$ (b) $7.4 \times 10^{-8}M$
(a) 1. Write the $K_{sp}$ expression: $AgI(s) \lt -- \gt 1Ag^{+}(aq) + 1I^-(aq)$ $8.3 \times 10^{-17} = [Ag^{+}]^ 1[I^-]^ 1$ $8.3 \times 10^{-17} = (9.1 \times 10^{-9})^ 1( 1S)^ 1$ 2. Find the molar solubility. $8.3 \times 10^{-17}= (9.1 \times 10^{-9})^ 1 \times ( 1S)^ 1$ $\frac{8.3 \times 10^{-17}}{9.1 \times 10^{-9}} = ( 1S)^ 1$ $9;1 \times 10^{-9} = ( 1S)^ 1$ $9.1 \times 10^{-9} = S$ ------ (b) 1. Write the $K_{sp}$ expression: $Al(OH)_3(s) \lt -- \gt 3OH^{-}(aq) + 1Al^{3+}(aq)$ $1.8 \times 10^{-33} = [OH^{-}]^ 3[Al^{3+}]^ 1$ $1.8 \times 10^{-33} = (2.9 \times 10^{-9})^ 3( 1S)^ 1$ 2. Find the molar solubility. $1.8 \times 10^{-33}= (2.9 \times 10^{-9})^ 3 \times ( 1S)^ 1$ $1.8 \times 10^{-33}= 2.4 \times 10^{-36} \times ( 1S)^ 1$ $\frac{1.8 \times 10^{-33}}{2.4 \times 10^{-36}} = ( 1S)^ 1$ $7.4 \times 10^{-8} = ( 1S)^ 1$ $7.4 \times 10^{-8} = S$