1. Tardigrade
  2. Question
  3. Chemistry
  4. The heat of neutralization of HCl by NaOH is -55.9 kJ mol-1 and that of HCN is -12.1 kJ; the energy of dissociation of HCN is

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Q. The heat of neutralization of HCl by NaOH is $ -55.9\,kJ\,mo{{l}^{-1}} $ and that of HCN is -12.1 kJ; the energy of dissociation of HCN is

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Solution:

$ {{H}^{+}}+O{{H}^{-}}\xrightarrow[{}]{{}}{{H}_{2}}O;\Delta H=-55.9kJ $ ?(i) $ HCN+O{{H}^{-}}\to {{H}_{2}}O+C{{N}^{-}};\Delta H=-12.1\,kJ $ ?(ii) On revers Eq. (i) and then adding to Eq. (ii), we get $ HCN\xrightarrow[{}]{{}}{{H}^{+}}+C{{N}^{-}};\Delta H=+43.8kJ $