Dissociation Energy of F2

The dissociation energy of F₂ has been determined mass spectrometrically. The heat of formation of fluorine, ${\mathrm{\Delta H}}_f^{°}\mathrm{(F)}$ , was determined from measurements of both the appearance potentials and translational energies of the products resulting from electron impact, including both positive and negative ions. One can derive values for the dissociation energy from each of the possible processes, namely: (1) dissociative electron attachment, (2) ion‐pair formation, and (3) dissociative ionization. The values are in excellent agreement and establish ${\mathrm{D°(F}}_2\text{)=37.5\hspace{0.17em}±\hspace{0.17em}2.3}\mathrm{kcal}/\mathrm{mol}$ .