The Department of Basic Education’s NSC Diagnostic Reports break down exactly where Physical Sciences candidates lose marks, question by question. Comparing the organic chemistry sections — Questions 2 to 4 in Paper 2 — across the 2024 and 2025 reports shows how much of the same ground keeps getting lost, and where new problems are emerging.
Q2 – Organic Nomenclature & Structures
| 2024 | 2025 | |
|---|---|---|
| Functional groups | Didn’t know the formyl group = aldehydes | Didn’t know the hydroxyl group = alcohols |
| Condensed → structural | Couldn’t convert condensed formulae (compounds E, F, G) to work out the homologous series | Same struggle — couldn’t convert condensed formulae to identify main chain/functional groups (e.g. spotting a triple bond) |
| IUPAC naming | Wrong names for compounds B and E; wrote “propanol” instead of “propan-1-ol” | Broader spread of naming errors: numbering from the wrong end, substituents not alphabetised, wrong suffixes (e.g. “but-2-one” instead of “butan-2-one”), missing hyphens/punctuation |
| Isomerism | Could define functional isomer but couldn’t apply it to identify examples from a list | Same gap persists, plus a new specific error: drawing the same molecule in a different orientation or a mirror image and calling it an isomer |
| Stoichiometry | Not flagged as an issue in this question | New this year: Q2.3.2 poorly answered — candidates couldn’t identify the limiting reagent and wrongly assumed STP (used 22,4 dm³·mol⁻¹) |
Q3 – Physical Properties of Organic Compounds
| 2024 | 2025 | |
|---|---|---|
| Bonds vs forces | “Breaking the bonds” used instead of “overcoming intermolecular forces” | Identical error, worded almost the same way in the report |
| Comparative language | Missing superlatives (“weakest”/”strongest”) when comparing three compounds | Same issue, described as poor use of comparative vs. superlative degree |
| Identifying the variable | Couldn’t identify what was being varied (chain length vs. functional group) | Same gap explicitly repeated |
| Type of IMF | Not singled out as its own error | New/sharper this year: candidates confused hydrogen bonding with dipole-dipole forces, and didn’t know esters have dipole-dipole forces while carboxylic acids have hydrogen bonding |
Q4 – Reactions of Organic Compounds
| 2024 | 2025 | |
|---|---|---|
| Flow diagrams | Couldn’t work out where to start in the sequence; failed to see reaction I’s product as reaction II’s reactant | Same core problem, described almost identically |
| Cracking definition | Poorly worded — “larger/smaller” used instead of “longer/shorter”; word “hydrocarbon/alkane” often omitted | Still poorly defined, though the report frames it more generally (the definition needs precision — “molecules”, “compounds”, “alkanes” and “hydrocarbons” can’t be used interchangeably) |
| Formula types | Confused molecular, condensed and structural formulae | Identical error, still present |
| Halogen/haloalkane naming | Specific confusion between “halide”, “halogen”, and “haloalkane” terminology | Not mentioned this year |
| Saturation test | Not raised as an error in 2024 | New this year: bromine water test — candidates said “colour change” instead of the required “colourless”/”decolourises” |
What Stands Out Across Both Years
The persistent problems are almost entirely the same: converting condensed to structural formulae, applying isomer definitions rather than just stating them, “breaking bonds” instead of “overcoming intermolecular forces”, missing superlative language in comparisons, and confusing formula types. These have shown up in back-to-back reports, which the DBE itself flags as a sign that classroom correction hasn’t stuck.
The genuinely new items in 2025 are the stoichiometry error in Q2 (assuming STP incorrectly) and the sharper IMF-type confusion in Q3 — both suggest candidates are pattern-matching definitions rather than reasoning through the chemistry, which lines up with the report’s broader complaint about conceptual understanding across the whole paper.