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Reactions of acids

7 lessons in Chemical changes.

36 exam questions · 59 marks

4.5 Acids, alkalis and the pH scale What makes a solution acidic or alkaline, the pH scale from 0 to 14, measuring pH with universal indicator or a pH probe, and the colours of common indicators. AQA Edexcel OCR 4.6 Neutralisation and the reactions of acids How acids react with metals, metal oxides, metal hydroxides and metal carbonates, naming and writing formulae for salts, the ionic equation for neutralisation, and the tests for hydrogen and carbon dioxide. AQA Edexcel OCR 4.7 Required practical: making a soluble salt How to make pure, dry crystals of a soluble salt such as copper sulfate from an insoluble base and an acid: warming the acid, adding excess base, filtering, evaporating and crystallising, and why each step is done. AQA Edexcel OCR 4.8 Core practical: pH change in neutralisation Edexcel core practical: adding calcium hydroxide a little at a time to dilute hydrochloric acid, measuring the pH after each addition, and plotting and explaining the pH curve. Edexcel 4.9 Strong and weak acids The difference between strong and weak acids (full or partial ionisation), the difference between concentrated and dilute, and how pH changes by one unit for each factor of 10 change in hydrogen ion concentration. Higher only AQA Edexcel OCR 4.10 Solubility rules and preparing salts The general rules for which common salts are soluble in water, predicting precipitates, and the methods for preparing a soluble salt by titration and an insoluble salt by precipitation. Edexcel 4.11 Titrations How to carry out an accurate acid-alkali titration using a pipette, burette and indicator, how to read a burette, and how to identify concordant titres and calculate a mean titre. AQA Edexcel OCR