HSC Chemistry case studies
HSC Chemistry · Put your knowledge to work in context.
HSC Chemistry is a Stage 6 science course within the Higher School Certificate, the credential awarded to senior secondary students in New South Wales. NESA, the NSW Education Standards Authority, describes its role as setting syllabuses, assessments, teaching and school standards for all schools in NSW, and it characterises the HSC as a world-class credential that helps young adults on the path to work, training and further education. Chemistry is one of the Stage 6 science learning areas listed on NESA's site, and its syllabus is published through the NSW Curriculum website. The course builds understanding of matter and its transformations, moving from atomic and molecular structure through to how substances interact, react and are designed or synthesised for practical purposes. The HSC Chemistry case studies are 4 cases and about 1,528 words.
1Choosing an Indicator for a Weak Acid–Strong Base Titration
A student titrates 25.00 mL of 0.100 M ethanoic acid (Ka = 1.8 × 10⁻⁵) with 0.100 M sodium hydroxide. They have four indicators available: methyl orange (pH range 3.1–4.4), bromothymol blue (6.0–7.6), phenolphthalein (8.3–10.0) and alizarin yellow (10.1–12.0).
393 words, about 2 min2Explaining an Anomalous Boiling Point in a Homologous Series
A class compares boiling points of four liquids: butan-1-ol (bp 118 °C), butan-2-ol (bp 100 °C), 2-methylpropan-2-ol (bp 82 °C) and butan-1-amine (bp 78 °C). All four have similar molar mass (73–74 g mol⁻¹).
350 words, about 2 min3Deciding Whether a Reaction Is Spontaneous at a New Temperature
An industrial team studies the contact process step SO₂(g) + ½O₂(g) ⇌ SO₃(g). At 298 K the standard enthalpy change is ΔH° = −99 kJ mol⁻¹ and the standard entropy change is ΔS° = −94 J K⁻¹ mol⁻¹.
391 words, about 2 min4Designing a Synthesis Route with Protecting Groups
A team must convert 4-aminobenzoic acid into a compound in which the carboxylic acid is converted to an ester (ethyl 4-aminobenzoate) while the amino group is left unchanged. Direct acid-catalysed esterification with ethanol and sulfuric acid gives a poor yield and a dark tar.
394 words, about 2 min