Q10 = (R₂/R₁)^(10/(T₂−T₁))
Q10 measures how much a reaction rate changes for a 10°C temperature increase: Q10 = (R₂/R₁)^(10/(T₂−T₁)). Most chemical reactions have Q10 = 2-3, meaning the rate doubles or triples per 10°C rise (consistent with the Arrhenius equation). Biological systems typically show Q10 ≈ 2 for enzyme-catalyzed reactions below the denaturation temperature. Above optimal temperature, enzymes denature and rates drop sharply. Q10 is used in: food science (shelf life prediction — the "Q10 rule" for food spoilage), ecology (predicting metabolic rates of ectotherms), electronics (failure rate acceleration), and pharmacology (drug degradation kinetics). A Q10 of exactly 1 means the process is temperature-independent.