<p>The pressure-volume work for an ideal gas can be calculated by using the expression w = -<math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mo>&#8747;</mo><msub><mi>V</mi><mi>i</mi></msub><msub><mi>V</mi><mi>f</mi></msub></msubsup><mo>&#160;</mo><msub><mi>p</mi><mrow><mi>e</mi><mi>x</mi><mi>t</mi><mo>.</mo></mrow></msub><mi>d</mi><mi>V</mi></math>. The work can also be calculated from the pV - plot by using the area under the curve within the specified limits. When an ideal gas is compressed (a) reversibly or (b) irreversibly from volume&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>V</mi><mi>i</mi></msub><mo>&#160;</mo><mi>t</mi><mi>o</mi><mo>&#160;</mo><msub><mi>V</mi><mi>f</mi></msub></math>, choose the correct option:</p>