alleryAt 298 K, water has Kw = 10⁻¹⁴. Concentration of H+ in pure water:
A10⁻¹⁴ M
B10⁻⁷ M
C10⁻¹ M
DVariable
Answer & Solution
Correct answer: B. 10⁻⁷ M
In pure water at 25°C: H2O ⇌ H+ + OH-, Kw = [H+][OH-] = 10⁻¹⁴.
Since [H+] = [OH-] in pure water: [H+]² = 10⁻¹⁴, [H+] = 10⁻⁷ M. Hence neutral pH = 7.
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