Answer:
a) S = 1.7099 E-11 g/L
b) S = 8.88 E-31 g/L
Explanation:
a) in water:
solubility: S S 2S
Ksp = [ Ca²+ ] * [ PO4²-]² = ( S ) * ( 2S )² = 4S³ = 2.0 E-32
⇒ S = ∛ (2.0 E-32 / 4) = 1.7099 E-11 g/L
b) 0.150 M sln CaCH:
0.15 0.15 0.15
Ksp = ( S ) * ( 2S + 0.15 )² ......... we despise solubility as adding
⇒ Ksp = ( S ) * ( 0.15 )² = 2.0 E-32
⇒ S = 2.0 E-32 / 0.0225 = 8.88 E-31 g/L