At 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.
Related questions
For the dissociation of a weak acid HA, the degree of dissociation α is given (approximateAccording to Brønsted-Lowry, an acid is a substance that:If Q (reaction quotient) > K_c at some instant, the reaction will:Le Chatelier's principle states that a system at equilibrium under stress:K_sp of a sparingly soluble salt AB at 25 °C is 4 × 10⁻¹⁰. Molar solubility s of AB is:A buffer solution is most resistant to pH change when:K_w (ionic product of water at 25 °C) is:The pH of a 0.01 M HCl solution is: