Answer:
a. 0,035M
Step-by-step explanation:
For the reaction:
Ba(OH)₂(s) ⇄ Ba²⁺(aq) + 2OH⁻(aq)
Ksp is defined as:
Ksp = [Ba²⁺] [OH⁻]²
5x10⁻³ = [Ba²⁺] [OH⁻]²
if is added a solution of 1M of Ba²⁺:
5x10⁻³ = [1M] [OH⁻]²
The addition of barium hydroxide Ba(OH)₂ gives:
[Ba²⁺] = 1M + x
[OH⁻]² = 2x
Replacing:
5x10⁻³ = [1 + x] [2x]²
5x10⁻³ = 4x² + 4x³
Solutions are:
x = -1,00 M
x = -0,036 M
x = 0,035 M → Right answer, there are not negative concentrations.
Thus, solubility is
a. 0,035M
I hope it helps!