Verified Solution • 2025–26 Session moderate

QJEEM21Ph520b: JEE Main 2021 Physics - Class 11 JEEM21Ph520b Solution: One mole of an ideal gas is taken through an adiabatic process…

One mole of an ideal gas is taken through an adiabatic process where the temperature rises from 27∘ C to 37∘ C. If the ideal gas is composed of polyatomic molecule that has 4 vibrational modes, which of the following is true? [R = 8.314 J mol−1 k−1]

Multiple Choice Options

  • A work done by the gas is close to 332 J
  • B work done on the gas is close to 582 J
  • C work done by the gas is close to 582 J
  • D work done on the gas is close to 332 J

Step-by-Step Verified Solution

Since, each vibrational mode, corresponds to two degrees of freedom, hence, f = 3 (trans.) + 3 (rot.) + 4 × 2 (vib.) = 14

& γ=1+2f

γ=1+214=87

W=nRΔTγ−1=−582

As W < 0. work is done on the gas.

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