Which change causes the pH of 25.0 cm3 of 5.00 × 10-4 mol dm-3 Ba(OH)2(aq)\text{Ba(OH)}_2(\text{aq})Ba(OH)2(aq) to decrease to 10.00 at 298 K? (Take Kw=1.00×10−14 mol2 dm−6K_{\text{w}} = 1.00 \times 10^{-14}\text{ mol}^2\text{ dm}^{-6}Kw=1.00×10−14 mol2 dm−6 at 298 K)
adding 100 cm3100\text{ cm}^3100 cm3 of distilled water
adding 125 cm3125\text{ cm}^3125 cm3 of distilled water
adding 225 cm3225\text{ cm}^3225 cm3 of distilled water
adding 250 cm3250\text{ cm}^3250 cm3 of distilled water
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.