0620/42 · May/June 2025
Theory (Extended) · 80 marks · 6 questions
- Question 18 marks
Short facts as numbers: composition of air, Contact process temperature, metals and halogens in the Periodic Table, fermentation, and isomers of an alkene.
- Question 216 marks
Covalent bonding: what a covalent bond is, a dot-and-cross diagram for chlorine(I) oxide, and why simple molecules have low boiling points.
- Question 315 marks
Electrolysis of copper(II) sulfate solution with inert electrodes: electrode changes, products and half-equations.
- Question 49 marks
Extracting chromium from its ore with carbon, stainless steel as an alloy, and transition metal properties.
- Question 514 marks
Trends in the alkali metals, and ionic bonding in sodium sulfide.
- Question 618 marks
Ethene and the alkenes: homologous series, combustion, hydration to ethanol, and addition reactions.