2025 · Paper 2 · Chemistry
Question 11
The printed question, the official key, and each model’s JSON answer plus the reasoning it wrote.
ChemistryPaper 2Numerical
Q11
Official 15.5 – 16.5
Model answers
Claude Fable 5.1
Anthropic
Correct4 / 4
16
Claude Fable 5.1 reasoning
**Freundlich isotherm:** x/m = k·C^(1/n), so log(x/m) = log k + (1/n) log C. Using the two data points: (1/n) = [log 10 − log 4] / [log 16 − log 10] = (1 − 0.6)/(1.2 − 1) = 0.4/0.2 = 2 So x/m = k·C². From C = 10, x/m = 4: k = 4/100 = 0.04. At C = 20 mg g⁻¹: x/m = 0.04 × 400 = **16 mg g⁻¹**
GPT 6 Astra
OpenAI
Correct4 / 4
16
GPT 6 Astra reasoning
No written reasoning was returned for this item.
GPT 5.6 Luna
OpenAI
Correct4 / 4
16
GPT 5.6 Luna reasoning
No written reasoning was returned for this item.