Import Question JSON

$\text{HINT: Bond dissociation energy of F}_2 \text{ is less than Br}_2 \text{ and Cl}_2$$ $\text{Explanation:}$ $\text{(i) In general as the bond length increases, the bond dissociation energy decreases. But the bond dissociation energy of F}_2 \text{ is less than that of Cl}_2\text{.}$ $\text{Due to the exceptionally small size of the Fluorine and high interelectronic repulsions, the energy required to dissociate the F-F bond is not the highest as expected and the following order is followed.}$ $\text{Bond dissociation energy order : Cl}_2> \text{Br}_2> \text{F}_2> \text{I}_2$ $\text{X-X Bond: F-F, Cl-Cl, Br-Br, I-I}$ $\text{Bond length (Å): 1.42, 1.99, 2.28, 2.67}$ $\text{Bond dissociation energy (kcal/mol): 38, 57, 45.5, 35.6}$ $\text{(ii) As we move from left to right, the electronegativity of elements increases, so they have less tendency to lose electrons and non-metallic character of elements increases.}$ $\text{So as the non-metallic character increases so oxidizing power of elements increases from left to right along a period.}$ $\text{STEP 3: Although fluorine is the smallest atom of the halogen series, due to its higher electronegativity and high electron density, it can't accept an electron easily.}$ $\text{But, chlorine is large in size and has comparatively low value of electronegativity than fluorine. Thus, it accepts an electron easily and has the highest electron gain enthalpy value.}$ $\text{Thus, electron gain enthalpy order is : F < Cl > Br > I}$