2025 · Paper 1 · Chemistry
Question 10
The printed question, the official key, and each model’s JSON answer plus the reasoning it wrote.
ChemistryPaper 1Numerical
Q10
Official -7.2 – -7
Model answers
Claude Fable 5.1
Anthropic
Correct4 / 4
-7.1
Claude Fable 5.1 reasoning
Van der Waals equation: (P + a/Vm²)(Vm − b) = RT Expanding: P·Vm³ − (Pb + RT)·Vm² + a·Vm − ab = 0 Coefficient of Vm²: −(Pb + RT) = −(300 × 0.060 + 0.082 × 300) = −(18 + 24.6) = −42.6 Coefficient of Vm: a = 6.0 Ratio = −42.6 / 6.0 = −7.1 mol dm⁻³ The magnitude is 7.1; with sign, the ratio is −7.1.
GPT 6 Astra
OpenAI
Correct4 / 4
-7.1
GPT 6 Astra reasoning
No written reasoning was returned for this item.
GPT 5.6 Luna
OpenAI
Correct4 / 4
-7.1
GPT 5.6 Luna reasoning
No written reasoning was returned for this item.