2. Questions Bank
  3. JEE Main & Advanced
  4. Chemistry
  5. Thermodynamics / रासायनिक उष्मागतिकी

JEE Main & Advanced Chemistry Thermodynamics / रासायनिक उष्मागतिकी Question Bank Heat of reaction

  • question_answer
    \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\,\,\to \,\,{{H}_{2}}O(l)\]; \[\Delta H\] at 298 K = ? 285.8 kJ The molar enthalpy of vaporisation of water at 1 atm and \[{{25}^{o}}C\] is 44 kJ. The standard enthalpy of formation of 1 mole of water vapour at \[{{25}^{o}}C\] is    [KCET 1999]

    A)                 ? 241.8 kJ            

    B)                 241.8 kJ

    C)                 329.8 kJ

    D)                 ?329.8 kJ

    Correct Answer: A

    Solution :

           \[{{H}_{2}}+\frac{1}{2}{{O}_{2}}\to {{H}_{2}}{{O}_{(l)}};\,\,\,\Delta H=-285.8\,KJ\]            \[{{H}_{2}}{{O}_{(l)}}\to {{H}_{2}}{{O}_{(g)}};\,\,\,\Delta H=44\,KJ\]                                 \[\therefore {{H}_{2}}+\frac{1}{2}{{O}_{2}}\to {{H}_{2}}{{O}_{(g)}}; & \,\,\,\Delta {{H}^{o}}=-241.8\,KJ\]


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