Answer:
The correct answer is (c) 1 × 10⁻⁹ M
Explanation:
Hydroxide ion = OH⁻
Hydrogen ion = H⁺
The autoionization equilibrium of water at 25ºC has a water constant Kw which is expressed as follows:
Kw = [H⁺] x [OH⁻]= 1 x 10⁻¹⁴
If we know the concentration of hydroxide ion ([OH⁻]) we can calculate the hydrogen ion concentration ([H⁺]) as follows:
[H⁺] = Kw/[OH⁻]= (1 x 10⁻¹⁴)/1 x 10⁻⁵ M= 1 x 10⁻⁹ M
