Answer in General Chemistry for Joy #153009
March 17th, 2023
“AX_{3(s)} u21cc A^{3+}_{(aq)} + 3X^-_{(aq)}”
Ksp = 1.0 x 10⁻³³
Let us denote the solubility of AX3 as S molL–1.
[A3+] = S
[X–] = 3S
Ksp = [A3+][X–]³ = [S][3S]³ = 27S⁴
1.0 x 10⁻³³ = 27S⁴
S = 2.47×10–⁹ M
Molar mass of AX3 = 78.0 g/mol
S = 2.47 × 10-9 moldm-3 × 78.0 g/mol = 1.93 × 10-7 gdm-3 = 0.193 mg per 1L
Therefore, the the solubility of AX₃ at 25⁰C is 0.193 mg/L