2. Solved Papers
  3. Haryana PMT

Haryana PMT Haryana PMT Solved Paper-2001

  • question_answer
    The \[H-H\] bond energy is \[430\text{ }kJ\text{ }mol{{e}^{-1}}\] and \[Cl-Cl\] bond energy is \[240\text{ }kJ\text{ }mol{{e}^{-1}}\], \[\Delta H\] for \[HCl\] is \[-90kJ\]. The \[H-Cl\] bond energy is about:

    A)  \[180kJ\text{ }mol{{e}^{-1}}\]

    B)  \[360kJ\text{ }mol{{e}^{-1}}\]

    C)  \[213kJ\text{ }mol{{e}^{-1}}\]

    D)  \[425kJ\text{ }mol{{e}^{-1}}\]

    Correct Answer: D

    Solution :

                    \[\frac{1}{2}{{H}_{2}}+\frac{1}{2}C{{l}_{2}}\xrightarrow{{}}HCl;\]   \[\Delta H=-90kJ\] \[-\Delta H=\frac{1}{2}B.E.(H-H)+\frac{1}{2}B.E(Cl-Cl)\] or \[-90=\frac{1}{2}[430]+\frac{1}{2}[240]-B.E.(H-Cl)\] or \[-90=215+120-B.E.(H-Cl)\]                 \[B.E.(H-Cl)=215+120+90\]                 \[=425kJ\,mol{{e}^{-1}}\]


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