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SingaporeChemistry

Inorganic Chemistry

7 dot points across 7 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do the trends in Group 17 explain the relative oxidising power of the halogens and the behaviour of their compounds?

Describe the trends down Group 17 in volatility, colour and oxidising power, explain displacement reactions of halogens and halides, describe the reactions of halide ions with silver nitrate and with concentrated sulfuric acid, and the disproportionation of chlorine
A focused answer to the H2 Chemistry learning outcome on Group 17. Trends in volatility, colour and oxidising power down the group, halogen-halide displacement, the silver nitrate and concentrated sulfuric acid tests for halides, and the disproportionation of chlorine in alkali.
10 min answer →

How and why do the properties of the Group 2 elements and their compounds change down the group?

Describe the trends down Group 2 in reactivity with water and oxygen, the thermal stability and solubility of the carbonates, nitrates, hydroxides and sulfates, and explain these trends in terms of ionic radius and charge density
A focused answer to the H2 Chemistry learning outcome on Group 2. Trends in reactivity with water, thermal stability of carbonates and nitrates, solubility of hydroxides and sulfates, all explained through ionic radius and cation charge density (polarising power).
9 min answer →

Why is nitrogen so unreactive, and how do its key compounds behave and affect the environment?

Explain the unreactivity of nitrogen, describe the formation and basicity of ammonia, the industrial Haber process and the formation of nitrogen oxides, and discuss the environmental impact of nitrogen oxides and ammonium fertilisers
A focused answer to the H2 Chemistry learning outcome on nitrogen. The inertness of the N triple bond, the basicity of ammonia and its lone pair, the Haber process, the formation of nitrogen oxides in engines, and the environmental impact of NOx and nitrate fertilisers.
9 min answer →

How do the properties of the Period 3 elements and their oxides and chlorides vary across the period, and why?

Describe and explain the periodic variation across Period 3 in atomic radius, ionic radius, melting point and electrical conductivity, and the trends in the bonding, structure and acid-base behaviour of the oxides and chlorides
A focused answer to the H2 Chemistry learning outcome on Period 3 periodicity. Trends in atomic and ionic radius, melting point and conductivity across Na to Ar, and the change in bonding, structure and acid-base behaviour of the oxides and chlorides from ionic to covalent.
10 min answer →

How is sulfuric acid manufactured, and how do sulfur oxides affect the environment?

Describe the formation of sulfur dioxide and its role in acid rain, outline the Contact process for manufacturing sulfuric acid, and explain the use of sulfur dioxide as a preservative and the methods used to control sulfur emissions
A focused answer to the H2 Chemistry learning outcome on sulfur. The formation of sulfur dioxide and its role in acid rain, the Contact process for making sulfuric acid with its equilibrium reasoning, the use of sulfur dioxide as a preservative, and the control of sulfur emissions by flue-gas desulfurisation.
9 min answer →

What gives the transition elements their characteristic variable oxidation states and catalytic behaviour?

Define a transition element, explain the existence of variable oxidation states from the close energies of the 3d and 4s subshells, and describe their use as catalysts and the role of variable oxidation states in catalysis
A focused answer to the H2 Chemistry learning outcome on transition elements. The definition (partially filled d subshell in an ion), why variable oxidation states arise from close 3d and 4s energies, and how variable oxidation states enable homogeneous and heterogeneous catalysis.
9 min answer →

How do transition metals form coloured complex ions, and what controls the colour observed?

Describe the formation of complex ions with ligands, explain coordination number and shape, account for the origin of colour in terms of d orbital splitting and d-d transitions, and describe ligand exchange reactions
A focused answer to the H2 Chemistry learning outcome on transition-metal complexes. Ligands and dative bonding, coordination number and shape, the origin of colour from d orbital splitting and d-d transitions, and ligand exchange reactions with colour changes.
10 min answer →