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An ideal gas expands in volume from 10-3 m3 to 10-2 m3 at 300 K against a constant pressure of 105 N m-2 . The work done is:

  • Option 1)

    900 kJ

  • Option 2)

    -900 kJ

  • Option 3)

    270 kJ

  • Option 4)

    -900 J

 

Answers (1)

best_answer

As we discussed in concept

Work Done for Irreversible Isothermal Expansion of an ideal gas -

W= -P_{ext}\left ( V_{f} -V_{i}\right )

- wherein

P_{ext} may be equal to P_{f} or may not be equal to P_{f}, but work done is always calculated by P_{ext}

 

 Work done due to change in volume when pressure is constant

W=\:-P\Delta V

      = -\:P(V_{f}-V_{i})

     = -\:10^{5}(10^{-2}-10^{-3})

     = - 900 J


Option 1)

900 kJ

This option is incorrect.

Option 2)

-900 kJ

This option is incorrect.

Option 3)

270 kJ

This option is incorrect.

Option 4)

-900 J

This option is correct.

Posted by

divya.saini

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