2025 · Paper 2 · Chemistry
Question 14
The printed question, the official key, and each model’s JSON answer plus the reasoning it wrote.
ChemistryPaper 2Numerical
Q14
Official 105.4 – 105.6
Model answers
Claude Fable 5.1
Anthropic
Correct4 / 4
105.5
Claude Fable 5.1 reasoning
Combustion of butane: C₄H₁₀ + (13/2) O₂ → 4 CO₂ + 5 H₂O ΔG° = 4(−394) + 5(−237) − (−18) = −1576 − 1185 + 18 = −2743 kJ/mol Electrons transferred: carbon goes from oxidation state −2.5 in C₄H₁₀ to +4 in CO₂, i.e., 6.5 per C × 4 = 26 electrons (equivalently, 13/2 O₂ × 4 e⁻ = 26). E° = −ΔG°/(nF) = 2743×10³ / (26 F) = (105.5/F) × 10³ V So X = 105.5
GPT 6 Astra
OpenAI
Correct4 / 4
105.5
GPT 6 Astra reasoning
No written reasoning was returned for this item.
GPT 5.6 Luna
OpenAI
Correct4 / 4
105.5
GPT 5.6 Luna reasoning
No written reasoning was returned for this item.