What [Ag+] is needed to begin precipitating Ag2SO4 (s) from a .0073 M SO4^-2 solution?

Question

What [Ag+] is needed to begin precipitating Ag2SO4 (s) from a .0073 M SO4^-2 solution?

Ksp of Ag2SO4 = 1.6 x 10^-5

Answer 1

Ag₂SO₄(s) <==> 2Ag⁺(aq) + SO₄^2-(aq)

Ksp = 1.6x10^-5 = [Ag⁺]²[SO₄^2-]

We know the concentration of SO₄^2- is 0.0073 M, so we can solve for [Ag⁺]

1.6x10^-5 = (x)²(0.0073)

x² = 1.6x10^-5/0.0073 = 2.2x10^-3

x = [Ag⁺] = 4.7x10^-2 M