2. Sample Papers
  3. KVPY

KVPY Sample Paper KVPY Stream-SX Model Paper-28

  • question_answer
    The lattice energy of NaCl (s) is 756 kJ/mole. The dissolution of the solid in water to form ions is endothermic to the extent of 4 kJ/mol. If the hydration energy of \[N{{a}^{+}}\]and \[C{{l}^{-}}\]are in the ratio 6 : 5, then the heat of hydration value of \[N{{a}^{+}}\]ion is -

    A) \[-\,410\,\,kJ\,\,mo{{l}^{-1}}\]

    B) \[-\,752\,\,kJ\,\,mo{{l}^{-1}}\]

    C) \[-\,820\,\,kJ\,\,mo{{l}^{-1}}\]

    D) \[-\,341.81\,\,kJ\,\,mo{{l}^{-1}}\]

    Correct Answer: A

    Solution :

    \[\Delta {{H}_{solution}}=\Delta {{H}_{1\,\,attice}}+\Delta {{H}_{Hydration}}\] \[\Delta {{H}_{hydration}}=4-756=-752\,\,kJ(a\,\,KJ))\] \[\Delta {{H}_{N{{a}^{+}}hydration}}=\frac{6a}{11}=\frac{6x-752}{11}=-\,410.18\,\,kJ\]


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