EAMCET Medical EAMCET Medical Solved Paper-2010

  • question_answer
    The order of bond energies in halogen molecules is

    A)  \[{{F}_{2}}<C{{l}_{2}}<B{{r}_{2}}<{{I}_{2}}\]

    B)  \[{{F}_{2}}>C{{l}_{2}}>B{{r}_{2}}>{{I}_{2}}\]

    C)  \[C{{l}_{2}}>B{{r}_{2}}>{{F}_{2}}>{{I}_{2}}\]

    D)  \[C{{l}_{2}}>{{F}_{2}}>B{{r}_{2}}>{{I}_{2}}\]

    Correct Answer: C

    Solution :

                     In general, as the bond length (or the size of atom) increases, bond dissociation energy   decreases. But the bond energy of \[\text{F }\!\!\_\!\!\text{  }\!\!\_\!\!\text{ F}\]bond is lesser as compared to \[\text{C}{{\text{l}}_{\text{2}}}\]and \[\text{B}{{\text{r}}_{2}}.\]This is because of greater inter electronic repulsions   between the lone pairs of electrons of two fluorine atoms. Such a repulsion is not found in case of other halogens. Thus, the order of bond energy is
                             \[C{{l}_{2}}\]  >  \[B{{r}_{2}}\] > \[{{F}_{2}}\] > \[{{I}_{2}}\]
    \[(k-cal/mol)\] 57 45.5 38 35.56


You need to login to perform this action.
You will be redirected in 3 sec spinner