HSC Chemistry 2025
Walkthrough of the 2025 HSC Chemistry paper. Section structure, calculation strategy, and common errors flagged in the NESA notes from marking centre.
- Marks
- 100
- Time
- 180 min
- Authority
- NESA
- Updated
What this paper assessed
HSC Chemistry is one paper of 100 marks across 180 minutes plus 5 minutes reading time. Section 1 is 20 multiple choice (20 marks). Section 2 is short and extended response (80 marks). The 2025 paper kept the established weighting across Modules 5 to 8.
Section strategy
Section 1 in 30 minutes. Section 2 at roughly 1.8 minutes per mark. Carry units through every line of every calculation; a unit error often costs the final mark even when the magnitude is correct.
Common errors flagged
The 2025 NESA notes from marking centre flagged shallow extended responses on industrial chemistry processes, weak use of the data sheet for solubility tests, and miscalculation of pH for weak acid solutions where candidates used the strong acid approximation.
What to do with this paper
Sit Section 1 in 30 minutes, then Section 2 in 150 minutes. Mark with the official guidelines and rebuild every calculation that lost more than half its marks. Keep an error log of common slips.
Use this paper well
- Sit the paper under exam conditions (180 minutes, 100 marks).
- Mark yourself against the official NESA marking notes.
- Compare against the Chemistry hub to find the syllabus dot points this paper tested.