The solubility of AgI in water is 2.35 micrograms in 1.0 L at 25 °C. What is the value of Ksp for AgI?

Molar mass of AgI = (108 + 127) g/mol = 235 g/mol
Molar solubility of AgI = (2.35/1000 g/L) / (235 g/mol) = 1.00 × 10⁻⁵ M

AgI(s)        ⇌      Ag⁺(aq)          +          I⁻(aq)         Ksp = ?
Initial:                    0 M                           0 M
Change:       +(1.00 × 10⁻⁵) M       +(1.00 × 10⁻⁵) M
Eqm:    　　　 1.00 × 10⁻⁵ M          1.00 × 10⁻⁵ M

At equilibrium:
Ksp
= [Ag⁺] [I⁻]
= (1.00 × 10⁻⁵)²
= 1.00 × 10⁻¹⁰