Q.

If the process carried out on one mole of monatomic ideal gas is shown in the figure PV-diagram with P0V0=13RT0, the correct match is,        [2019]

1 I → Q, II → R, III → S, IV → U  
2 I → S, II → R, III → Q, IV → T  
3 I → Q, II → R, III → P, IV → U  
4 I → Q, II → S, III → R, IV → U  

Ans.

(1)

I.  W1→2→3=W1→2+W2→3    [W2→3=0, ΔV=0]

=P0×V0+0

=P0V0=RT03    [∵P0V0=13RT0 given]

    ∴ I→Q

II.  ΔU1→2→3=ΔU1→2+ΔU2→3

=nCvΔT1→2+nCvΔT2→3

=1×3R2(Tf-Ti)1→2+1×3R2(Tf-Ti)2→3

=32[2P0V0-P0V0]+32[3P02×2V0-P0×2V0]

=3P0V0=3×13RT0=RT0

   II→R

III.  Q1→2→3=Q1→2+Q2→3=nCpΔT1→2+nCvΔT2→3

=52P0V0+1×32[3P02×2V0-P0(2V0)]

=82P0V0=82×RT03=43RT0

III→S

IV.  Q1→2=nCpΔT1→2=nCp(Tf-Ti)

=1×5R2[P0(2V0)R-P0V0R]    [∵PV=nRT]

=52P0V0=52(RT03)=5RT06

∴  IV→U