At 50 ∘C50\text{ }^\circ\text{C}50 ∘C the ionic product of water, Kw=5.48×10−14 mol2 dm−6K_w = 5.48 \times 10^{-14} \text{ mol}^2 \text{ dm}^{-6}Kw=5.48×10−14 mol2 dm−6.
Give the expression for KwK_wKw.
Calculate the pH of pure water at 50 ∘C50\text{ }^\circ\text{C}50 ∘C. Give your answer to 2 decimal places.
40.0 cm340.0\text{ cm}^340.0 cm3 of 0.120 mol dm−30.120\text{ mol dm}^{-3}0.120 mol dm−3 aqueous potassium hydroxide are mixed with 25.0 cm325.0\text{ cm}^325.0 cm3 of a 0.080 mol dm−30.080\text{ mol dm}^{-3}0.080 mol dm−3 solution of nitric acid. The temperature of the solution formed is 50 ∘C50\text{ }^\circ\text{C}50 ∘C.
Calculate the pH of the solution formed. Give your answer to 2 decimal places.
77 exam-style questions on AQA A Level Chemistry Acids and bases (A-level only), covering Brønsted–Lowry acid–base equilibria in aqueous solution (A-level only), Definition and determination of pH (A-level only), The ionic product of water, $K_w$ (A-level only), Weak acids and bases $K_a$ for weak acids (A-level only), pH curves, titrations and indicators (A-level only), and Buffer action (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.