The use of error propagation shows that the error in Δ r H will be about 76 kJ/mol times the experimental uncertainty in (ln K 1 − ln K 2), or about 110 kJ/mol times the uncertainty in the ln K values. Similar considerations apply to the entropy of reaction obtained from Δ r S = ⁠ 1 / T ⁠ (Δ H + RT ln K).