Q.

One mole of an ideal monoatomic gas is subjected to changes as shown in the graph. The magnitude of the work done (by the system or on the system) is ______ J (nearest integer)                  [2023]

Given: log 2 = 0.3
            ln 10 = 2.3


Ans.

(620)

W12=-1(40-20)=-20 bar lit.

W23=0

W31=-nRTln(V2V1)

             =-P1V1ln(V2V1)

              =-1×20 ln2040

               =20 ln 2

               =20×2.3×0.3=13.8 bar lit.

Wtotal=-20+13.8

           =-6.2 bar lit.  (1 bar lit.=100 J)

Wtotal=-6.2×100=-620 J