Three aqueous samples are collected at 40 °C, where the ionic product of water is Kw=2.92×10−14.
Sample X: pH = 6.50
Sample Y: [OH⁻] = 2.0 × 10⁻⁷ M
Sample Z: pOH = 7.40
Answer the following questions.
(a) Determine [H₃O⁺] for each sample, reporting answers in scientific notation with appropriate units.
(b) Calculate the pH of any sample for which it has not yet been stated.
(c) Calculate the pH of pure water (neutrality point) at 40 °C.
(d) Classify each sample as acidic, neutral, or basic relative to the neutrality point you calculated in part (c), and justify each classification quantitatively.
(e) Rank Samples X, Y, and Z from highest hydronium-ion concentration to lowest, citing numerical evidence in support of the ordering.