NEET Sample Paper NEET Sample Test Paper-52

  • question_answer
    Temperature of 1000 grams of nitrogen is raised from \[-20{}^\circ \,C\text{ }to\text{ }100{}^\circ \,C\] at constant pressure. Given: specific heat at constant volume \[{{C}_{v}}\text{ }=5\text{ }cal/mole\text{ }{}^\circ C\text{ }and\text{ }R=2\,Cal/mole\,{}^\circ C\]
    [a] Heat required in the process is 30 K Cal
    [b] Increase in the internal energy of gas is 21 Kcal
    [c] If process is at constant volume then heat required is 21 Kcal
    [d] external work done is 10 KCal

    A) a, d                              

    B) a, b, c

    C) c, d                              

    D) b, d

    Correct Answer: B

    Solution :

    [a] Heat required is- \[Q=nCp\Delta T=n\left( Cv+R \right)\Delta T\] \[=\,\,\frac{1000}{28}[5+2]\times 120=30\times {{10}^{3}}cal\] \[Q=30\text{ }Kcal\] [b] The increase in the internal energy is \[\Delta U\,\,=\,\,nCv\Delta T=\frac{1000}{28}\,\,\times 5\times 120\] \[=\text{ }21\text{ }Kcal\] [c] \[Q=nCv\Delta T+P\Delta V\] for constant volume \[\Delta V=0\] \[Q=nCv\Delta T=21\,Kcal\] external work done is \[W=Q-\Delta U=8.6\,\,KCal\]


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