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
    In order to decompose 9 g water 142.5 kJ heat is required. Hence the enthalpy of formation of water is                [KCET 2001]

    A)                 ? 142.5 kJ            

    B)                 + 142.5 kJ

    C)                 ? 285 kJ

    D)                 + 285 kJ

    Correct Answer: C

    Solution :

           For the decomposition of 9gm of water heat required \[=142.5\,kJ\]            we know \[{{H}_{2}}O=2+16=18\]            Therefore heat required for decomposition of 18gm water \[=\frac{18}{9}\times 142.5=285\,KJ\]                                 Than, enthalpy of formation of water is reverse of heat required = ? 285 kJ.


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