Required practical: investigate pH changes in weak acid and strong base or strong acid and weak base titrations.

In the subtopic pH curves, titrations and indicators (A-level only), this AQA A-Level Chemistry 7405 learning objective focuses on required practical: investigate pH changes in weak acid and strong base or strong acid and weak base titrations. It belongs to Acids and bases (A-level only), so revision should stay anchored to this exact subtopic rather than drifting into a generic GCSE-level chemistry summary. Approved keywords to use include titration, weak acid, strong base. Brønsted-Lowry acid. means a substance that donates a proton (H+) in a chemical reaction Avoid the mistake of students often confuse the formula for calculating pH, using the wrong relationship between pH and hydrogen ion concentration; instead, to calculate pH from hydrogen ion concentration, use the formula pH = -log[H⁺]. Substitute the hydrogen ion concentration into the formula and calculate the pH. For example, if [H⁺] = 0.01 mol/dm³, then pH = -log(0.01) = 2. Therefore, the pH is 2 For exam answers, when investigating pH changes during titrations, sketch the expected pH curve for a weak acid and strong base titration. Identify the equivalence point and the buffer region