What you’ll learn7 learning objectivesChoose one objective for a focused lesson, or study the complete topic.9.2.1Reactions of the elements with oxygen (to• Describe/write equations: the reactions of the elements with oxygen (to give Na2O, MgO, Al2O3, P4O10, SO2), chlorine (to give NaCl, MgCl2, Al Cl 3, SiCl4, PCl5) and water (Na and Mg only)Syllabus objective9.2.2The variation in the oxidation number• State/explain: the variation in the oxidation number of the oxides (Na2O, MgO, Al2O3, P4O10, SO2 and SO3 only) and chlorides (NaCl, MgCl2, Al Cl 3, SiCl4, PCl5 only) in terms of their outer shell (valence) electronsSyllabus objective9.2.3Reactions/equations: the reactions, if any,• Describe/write equations: the reactions, if any, of the oxides Na2O, MgO, Al2O3, SiO2, P4O10, SO2 and SO3 with water, including the likely pHs of the solutions obtainedSyllabus objective9.2.4Reactions/equations: the acid / base behaviour• Describe/explain/write equations: the acid / base behaviour of the oxides Na2O, MgO, Al2O3, P4O10, SO2 and SO3 and the hydroxides NaOH, Mg(OH)2 and Al (OH)3 including, where relevant, amphoteric behaviour in reactions with acids and bases (sodium hydroxide only)Syllabus objective9.2.5Reactions of the chlorides NaCl, MgCl2, Al• Describe/explain/write equations: the reactions of the chlorides NaCl, MgCl2, Al Cl 3, SiCl4, PCl5 with water including the likely pHs of the solutions obtainedSyllabus objective9.2.6Variations and trends in 9.2.2, 9.2.3, 9.2.4• Explain the variations and trends in 9.2.2, 9.2.3, 9.2.4 and 9.2.5 in terms of bonding and electronegativitySyllabus objective9.2.7Suggest the types of chemical bonding present• Suggest the types of chemical bonding present in the chlorides and oxides from observations of their chemical and physical propertiesSyllabus objective