NEET Chemistry Chemical Bonding and Molecular Structure / रासायनिक आबंधन एवं आणविक संरचना NEET PYQ-Chemical Bonding Molecular

  • question_answer
    Bond order of 1.5 is shown by                                                                  [AIPMT (S) 2012]

    A)  \[O_{2}^{+}\]                       

    B)  \[O_{2}^{-}\] 

    C)  \[O_{2}^{2-}\]                       

    D)       \[O_{2}^{{}}\]

    Correct Answer: B

    Solution :

    [a] MO configuration of \[O_{4}^{+}(8+8-1=15)\]
    \[=\sigma 1{{s}^{2}},\overset{*}{\mathop{\sigma }}\,1{{s}^{2}},\sigma 2{{s}^{2}},\overset{*}{\mathop{\sigma }}\,2s,\sigma 2p_{z}^{2},\]
    \[\pi 2p_{x}^{2}\approx \pi 2p_{y}^{2},\overset{*}{\mathop{\pi }}\,2p_{x}^{1}\approx \overset{*}{\mathop{\pi }}\,2p_{y}^{0}\]
                \[BO=\frac{{{N}_{b}}-{{N}_{a}}}{2}\]
     (where, \[{{N}_{b}}=\] number of electrons in bonding molecular orbital \[{{N}_{a}}=\] number of electrons in anti-bonding molecular orbital
    \[\therefore \]      \[BO=\frac{10-5}{2}=2.5\]Similarly,
    [b]\[O_{2}^{-}(8+8+1=17)\]
    so\[BO=\frac{{{N}_{b}}-{{N}_{a}}}{2}=\frac{10-7}{2}=1.5\]
    [c]\[O_{2}^{2=}(8+8+2=18)\]
    \[BO=\frac{{{N}_{b}}-{{N}_{a}}}{2}=\frac{10-8}{2}=1\]
    [d]\[{{O}_{2}}(8+8=16)\]
                \[BO=\frac{10-6}{2}=2\]
    Thus, \[O_{2}^{-}\] shows the bond order 1.5.


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