The ionic product of water, Kw=2.40×10−14 mol2 dm−6K_w = 2.40 \times 10^{-14}\text{ mol}^2\text{ dm}^{-6}Kw=2.40×10−14 mol2 dm−6 at physiological body temperature (37 ∘C37\ ^\circ\text{C}37 ∘C).
Which is the correct expression for KwK_wKw?
Calculate the pH of pure water at 37 ∘C37\ ^\circ\text{C}37 ∘C. Give your answer to two decimal places.
Suggest why this pure water at 37 ∘C37\ ^\circ\text{C}37 ∘C is neutral.
Calculate the pH of a 0.0120 mol dm-3 solution of barium hydroxide at 37 ∘C37\ ^\circ\text{C}37 ∘C. Give your answer to two decimal places.
The 0.0120 mol dm-3 barium hydroxide solution at 37 ∘C37\ ^\circ\text{C}37 ∘C was a saturated solution. A student added 0.0120 mol of strontium hydroxide to 1.00 dm3 of water at 37 ∘C37\ ^\circ\text{C}37 ∘C and stirred the mixture until no more solid dissolved. Predict whether the pH of this strontium hydroxide mixture is larger than, smaller than, or the same as the pH of the barium hydroxide solution. Explain your answer.
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.