Question

Account for the following
Bond disa association energy of F2 is less than that of Cl2​

Answer 1

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☑️The size of fluorine is smaller than Chlorine and bromine. Due to which there is higher electron density on Fluorine. ... Due to this repulsion between the electrons both the atoms want to move apart. Hence the bond can be cleaved easily and the bond dissociation energy is less..

☑️It is well known that the bond dissociation energy of F2 is sig- nificantly smaller than would be expected from extrapolation of the I2 , Br2 and Cl2 values (I2 : 35.6 kcal molÀ1, Br2 : 45.4, Cl2 : 57.2, F2 : 36.9).1 Indeed, the F–F bond is one of the weak- est of all covalent bonds.

☑️Bond energy of chlorine is greater than fluorine and enthalpy is the energy content of the system or molecules. So enthalpy of fluorine is less than chlorine. Answer: ... So, there is a large electron - electron repulsion in flourine which is less in case chlorine as in chlorine the last electron enters into 3rd shell.