A gas mixture consists of 2 moles of O 2 and 4 moles of Ar at temperature T . Neglecting all vibrational…

A gas mixture consists of 2 moles of O2 and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is ( R is universal gas constant)
  1. 4 RT
  2. 15 RT
  3. 9 RT
  4. 11 RT

Solution

For a gas having n moles of molecules with each f degrees of freedom at temperature T K, internal energy is U=12nfRT
  Total internal energy is
U=n1f12 RT+n2f22 RT
=2×52 RT+4×32RT
=5RT+6RT
U=11RT /

Asked in: NEET 2017

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