2. Solved Papers
  3. JCECE Medical

JCECE Medical JCECE Medical Solved Paper-2008

  • question_answer
    The correct order of increasing basic nature for the bases \[\text{N}{{\text{H}}_{\text{3}}}\text{,C}{{\text{H}}_{\text{3}}}\text{N}{{\text{H}}_{\text{2}}}\]and \[{{\text{(C}{{\text{H}}_{\text{3}}}\text{)}}_{\text{2}}}\text{NH}\]is

    A) \[C{{H}_{3}}N{{H}_{2}}<N{{H}_{3}}<{{(C{{H}_{3}})}_{2}}NH\]

    B)  \[{{(C{{H}_{3}})}_{2}}NH<N{{H}_{3}}<C{{H}_{3}}N{{H}_{2}}\]

    C)  \[N{{H}_{3}}<C{{H}_{3}}N{{H}_{2}}<{{(C{{H}_{3}})}_{2}}NH\]

    D)  \[C{{H}_{3}}N{{H}_{2}}<{{(C{{H}_{3}})}_{2}}NH<N{{H}_{3}}\]

    Correct Answer: C

    Solution :

     \[N{{H}_{3}},C{{H}_{3}}N{{H}_{2}},{{(C{{H}_{3}})}_{2}}NH\] \[{{(C{{H}_{3}})}_{2}}NH+{{H}_{2}}O{{(C{{H}_{3}})}_{2}}\overset{+}{\mathop{N}}\,{{H}_{2}}+O{{H}^{-}}\] \[{{\text{I}}^{\text{+}}}\]effect maximum, stabilization more, H-bond stability high, hence most basic \[C{{H}_{3}}N{{H}_{2}}+{{H}_{2}}OC{{H}_{3}}\overset{+}{\mathop{N}}\,{{H}_{3}}+O{{H}^{-}}\] \[N{{H}_{3}}+{{H}_{2}}ONH_{4}^{+}+O{{H}^{-}}\] \[{{K}_{1}}>{{K}_{2}}>{{K}_{3}}\] Hence, basicity order is \[{{(C{{H}_{3}})}_{2}}NH>C{{H}_{3}}N{{H}_{2}}>N{{H}_{3}}\]


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