7. Acids, bases and salts
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7.1 The characteristic properties of acids and bases
7.1.1Characteristic properties of acids in
• Describe characteristic properties of acids in terms of their reactions with: (a) metals (b) bases (c) carbonates
7.1.2Acids in terms of their effect on: (a)
• Describe acids in terms of their effect on: (a) litmus (b) thymolphthalein (c) methyl orange
7.1.3Bases are oxides or hydroxides of
• State: bases are oxides or hydroxides of metals and that alkalis are soluble bases
7.1.4Characteristic properties of bases in
• Describe characteristic properties of bases in terms of their reactions with: (a) acids (b) ammonium salts
7.1.5Alkalis in terms of their effect on
• Describe alkalis in terms of their effect on: (a) litmus (b) thymolphthalein (c) methyl orange
7.1.6Aqueous solutions of acids contain H+
• State: aqueous solutions of acids contain H+ ions and aqueous solutions of alkalis contain OH– ions
7.1.7To compare hydrogen ion concentration
• Describe how to compare hydrogen ion concentration, neutrality, relative acidity and relative alkalinity in terms of colour and pH using universal indicator paper
7.1.8Neutralisation reaction between an
• Describe neutralisation reaction between an acid and an alkali to produce water, H+ (aq) + OH– (aq) → H2O (l)
7.1.9Acids as proton donors and bases as
• Define acids as proton donors and bases as proton acceptors
7.1.10Strong acid as an acid that is
• Define a strong acid as an acid that is completely dissociated in aqueous solution and a weak acid as an acid that is partially dissociated in aqueous solution
7.1.11Hydrochloric acid is a strong acid, as
• State: hydrochloric acid is a strong acid, as shown by the symbol equation, HCl (aq) → H+(aq) + Cl –(aq)
7.1.12Ethanoic acid is a weak acid, as shown
• State: ethanoic acid is a weak acid, as shown by the symbol equation, CH3COOH(aq) ⇌ H+(aq) + CH3COO–(aq)
7.2 Oxides
7.2.1Classify oxides as acidic
• Classify oxides as acidic, including SO 2 and CO2, or basic, including CuO and CaO, related to metallic and non-metallic character
7.2.2Amphoteric oxides as oxides that react
• Describe amphoteric oxides as oxides that react with acids and with bases to produce a salt and water
7.2.3Classify Al 2O3 and ZnO as amphoteric
• Classify Al 2O3 and ZnO as amphoteric oxides
7.3 Preparation of salts
7.3.1Preparation, separation and
• Describe preparation, separation and purification of soluble salts by reaction of an acid with: (a) an alkali by titration (b) excess metal (c) excess insoluble base (d) excess insoluble carbonate
7.3.2Salt solubility rules: soluble
• Describe salt solubility rules: soluble sodium/potassium/ammonium salts and nitrates; chlorides except lead/silver; sulfates except barium/calcium/lead; insoluble carbonates except sodium/potassium/ammonium; insoluble hydroxides except sodium/potassium/ammonium/calcium (partial)
7.3.3Hydrated substance as a substance that
• Define a hydrated substance as a substance that is chemically combined with water and an anhydrous substance as a substance containing no water
7.3.4Preparation of insoluble salts by
• Describe preparation of insoluble salts by precipitation
7.3.5Term water of crystallisation as the
• Define the term water of crystallisation as the water molecules present in hydrated crystals, including CuSO4•5H2O and CoCl2•6H2O