Answer
is: pH value of solution is 11.85.
[OH⁻] = 7.1·10⁻³ M; equilibrium concentration of hydroxide anions.
[OH⁻]·[H⁺]
= Kw.
0.0071 mol/L · [H⁺] =
10⁻¹⁴ mol²/L².
[H⁺] = 10⁻¹⁴ mol²/L² ÷ 7.1·10⁻³ mol/L.
[H⁺] = 1.4·10⁻¹² mol/L.
pH
= -log[H⁺].
pH
= -log(1.4·10⁻¹² mol/L).
pH
= 11.85.
If
pH is less than seven, solution is acidic; greater than seven, solution is
basic; equal seven, solution is neutral.
