Abstract
Measurements of the equilibrium constant for the gas phase reaction F+Cl2=ClF+Cl by a Cl‐atom chemiluminescence technique yield ΔH°0= −3.27±0.24 kcal/mole. This result settles the existing uncertainty in the spectroscopic determination of D°0(ClF) in favor of the larger value, 60.35 kcal/mole.