Question

At 22 °C an excess amount of a generic metal hydroxide M(OH)2 is mixed with pure water. The resulting Sp Number sp

Answer 1

M(OH)2(s) <--> M²? (aq) + 2 OH?(aq)
Ksp = [M²?][OH?]²

1) Use the pH to get the pOH
14 – 10.36 = 3.64

2) Use the pOH to get the [OH?]
[OH?] = 10?pOH = 10^–3.64 = 2.291 x 10^–4

3) [M²?] is half the value of [OH?], therefore:
[M²?] = 2.291 x 10^–4 divided by 2 = 1.145 x 10^–4

4) Put values into Ksp expression
Ksp = (1.145 x 10^–4)(2.291 x 10^–4)²
Ksp = 6.012 x 10^–12