van't Hoff equation (temperature and K) (ln(K2/K1) = -(ΔH°/R)(1/T2 - 1/T1))
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ln(K2/K1) = -(ΔH°/R)(1/T2 - 1/T1)
What each symbol means
| Symbol | What it stands for |
|---|---|
| R | 8.314 J mol⁻¹ K⁻¹ |
| ΔH° | Standard enthalpy change of reaction (assumed ~constant over small ΔT) |
| T_1,T_2 | Absolute temperatures |
When to use this
Approximate form for narrow temperature range; ΔH° sign controls how K changes with T (endothermic: K rises with T).