2. Questions Bank
  3. NEET
  4. Chemistry
  5. Thermodynamics / रासायनिक उष्मागतिकी

NEET Chemistry Thermodynamics / रासायनिक उष्मागतिकी Question Bank Self Evaluation Test - Thermodynamics

  • question_answer
    Assuming that water vapour is an ideal gas, the internal energy change \[\left( \Delta U \right)\] when 1 mol of water is vapourised  at 1 bar pressure and \[100{}^\circ C,\] (given : molar enthalpy of vapourisation of water at 1 bar and \[373\text{ }K=41\text{ }kJ\text{ }mo{{l}^{-1}}\] and \[R=8.3\,J\,mo{{l}^{-1}}{{K}^{-1}}\]) will be

    A) \[41.00kJ\,mo{{l}^{-1}}\]        

    B) \[4.100kJ\,mo{{l}^{-1}}\]

    C) \[3.7904\text{ }kJ\text{ }mo{{l}^{-1}}\] 

    D) \[37.904\text{ }kJ\text{ }mo{{l}^{-1}}\]

    Correct Answer: D

    Solution :

    [d] Given \[\Delta H=41\text{ }kJ\text{ }mo{{l}^{-1}}=41000J\text{ }mo{{l}^{-1}}\] \[T=100{}^\circ C=273+100=373\text{ }K\] \[\Delta n=1\] \[\Delta U=\Delta H-\Delta nRT=41000-\left( 1\times 8.314\times 373 \right)\] \[=37898.88\,Jmo{{l}^{-1}}\simeq 37.9kJ\,mo{{l}^{-1}}\]


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