← Chemistry syllabus

EnglandChemistry

3.2 Inorganic chemistry

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How and why do the reactivity, solubility of hydroxides and solubility of sulfates change down Group 2?

The trend in atomic radius, first ionisation energy and melting point down Group 2. The reactions of Group 2 elements with water. The trend in solubility of the hydroxides and sulfates of Group 2 elements. Uses of magnesium in the extraction of titanium, of calcium hydroxide in agriculture, of barium sulfate in medicine and of Group 2 compounds in neutralising acidity.
A focused answer to the AQA A-Level Chemistry 3.2.2 specification points on Group 2. Covers the trends in atomic radius, ionisation energy and reactivity down the group, reactions with water, the opposite solubility trends of the hydroxides and sulfates, and the key uses of Group 2 compounds.
9 min answer →

Why does oxidising power decrease while reducing power of the halide ions increases down Group 7?

The trends in electronegativity and boiling point of the halogens. The trend in oxidising ability of the halogens down the group, including displacement reactions of halide ions in aqueous solution. The trend in reducing ability of the halide ions, including the reactions of solid sodium halides with concentrated sulfuric acid. The use of acidified silver nitrate to identify and distinguish halide ions, and the use of chlorine in water treatment.
A focused answer to the AQA A-Level Chemistry 3.2.3 specification points on Group 7. Covers the boiling point and electronegativity trends, the decrease in oxidising power down the group with displacement reactions, the increase in reducing power of the halide ions with concentrated sulfuric acid, the silver nitrate test and the use of chlorine in water treatment.
10 min answer →

How does the bonding in the oxides of Period 3 elements explain the change from basic to acidic behaviour across the period?

The reactions of the Period 3 elements sodium and magnesium with water. The reactions of the Period 3 elements with oxygen to form oxides. The structure and bonding of the Period 3 oxides and the trends in their melting points. The reactions of the oxides with water and the acid-base nature of the resulting solutions. The behaviour of the oxides as acids or bases in their reactions with acids and bases.
A focused answer to the AQA A-Level Chemistry 3.2.4 specification points on Period 3 elements and their oxides. Covers the reactions of sodium and magnesium with water, the reactions with oxygen, the structure and bonding of the oxides, their melting point trend, their reactions with water, and the change from basic to amphoteric to acidic across the period.
10 min answer →

Why do atomic radius, ionisation energy and melting point change in a repeating pattern across the periods of the periodic table?

The classification of an element as s, p, d or f block according to its outer electron configuration. Trends in atomic radius and first ionisation energy across Period 3 and down a group, explained by nuclear charge, shielding and atomic radius. The trend in melting point across Period 2 and Period 3, explained by the structure and bonding of the elements.
A focused answer to the AQA A-Level Chemistry 3.2.1 specification points on periodicity. Covers s, p, d and f block classification, the trends in atomic radius and first ionisation energy across Period 3 and down a group, and the melting point trend across Periods 2 and 3 explained by structure and bonding.
9 min answer →

Why are some aqueous metal-aqua ions more acidic than others, and how do their reactions with bases let us identify them?

The acidity of metal-aqua ions in terms of the charge density of the metal ion and the polarisation of coordinated water. The reactions of metal-aqua ions with bases such as sodium hydroxide and ammonia, and with carbonate ions. The amphoteric character of the aluminium hydroxide complex. The use of these reactions to identify metal ions in solution by the colours and behaviour of the precipitates formed.
A focused answer to the AQA A-Level Chemistry 3.2.6 specification points on reactions of ions in aqueous solution. Covers the acidity of metal-aqua ions and the link to charge density, the reactions of 2+ and 3+ aqua ions with sodium hydroxide, ammonia and carbonate, the amphoteric behaviour of aluminium hydroxide, and how the precipitate colours identify metal ions.
11 min answer →

What features of the d-block electron configuration give transition metals their variable oxidation states, coloured ions and catalytic activity?

The definition of a transition metal in terms of an incomplete d sub-shell. The characteristic properties of transition metals: complex formation, coloured ions, variable oxidation states and catalytic activity. The shapes of complex ions and the meaning of coordination number and ligand. Stereoisomerism in complexes. Ligand substitution reactions and the chelate effect. The origin of colour in transition metal ions and its use in colorimetry. The role of transition metals as homogeneous and heterogeneous catalysts.
A focused answer to the AQA A-Level Chemistry 3.2.5 specification points on transition metals. Covers the d-sub-shell definition, complex ions, ligands and coordination number, the shapes and stereoisomerism of complexes, ligand substitution and the chelate effect, the origin of colour and colorimetry, variable oxidation states and homogeneous and heterogeneous catalysis.
12 min answer →