Answer: pH = 6.77
Explanation:
1) Chemical equilibrium
- 2 H₂O (l) ⇄ H₃O⁺ (aq) + OH⁻ (aq)
2) Equilibrium constant, Kw
- By stoichiometry [H₃O⁺] = [OH⁻]. Call it x
- x = √ (2.92 × 10⁻¹⁴) = 1.709 × 10⁻⁷ M = [H₃O⁺]
3) pH
- pH = - log [H₃O⁺] = - log (1.709 × 10⁻⁷) = 6.77