Answer:
Hydroxide concentration of the sample is 1.3x10⁻⁶M
Explanation:
The equilibrium constant of water, Kw, is:
H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)
Kw is defined as:
Kw = 1.7x10⁻¹² = [H⁺] [OH⁻]
As the sample is of pure water, both H⁺ and OH⁻ ions have the same concentration because come from the same equilibrium, that is:
[H⁺] = [OH⁻]
We can write the Kw expression:
1.7x10⁻¹² = [OH⁻] [OH⁻]
1.7x10⁻¹² = [OH⁻]²
1.3x10⁻⁶M = [OH⁻]
