Q.

A perfect gas (0.1 mol) having Cv = 1.50R (independent of temperature) undergoes the above transformation from point 1 to point 4. If each step is reversible, the total work done (w) while going from point 1 to point 4 is (–) ___ J (nearest integer).  

[Given : R = 0.082 L atm K-1mol-1]                                                        [2025]


Ans.

(304)

1→2 and 3→4 are isochoric processes. For isochoric processes W(PΔV)=0

W2→3=-P(V3-V2)

=-3 atm (2 L-1 L)

=-3 atm L=-3×101.3 J=-303.9 J

W1→4=W1→2+W2→3+W3→4

=0-303.9 J+0=-303.9 J=-304 J