Q103 / 125 · BITSAT 2012 · Physics

The average translational kinetic energy of $\mathrm{O}_{2}$ (molar mass 32) molecules at a particular temperature is $0.048 \mathrm{eV}$. The translational kinetic energy of $\mathrm{N}_{2}$ (molar mass 28 ) molecules in $\mathrm{eV}$ at the same temperature is

  • A
    0.0015
  • B
    0.003
  • Correct answer
    C
    0.048
  • D
    0.768

Solution

Given, \(\mathrm{E}_{\mathrm{O}_{2}}=0.048 \mathrm{eV}\) We know that, Translational kinetic energy, \(\mathrm{E}=\frac{3}{2} \mathrm{KT}\) where, \(\mathrm{k}=\) Boltzmann constant \(\mathrm{T}=\) Temperature \(\therefore \mathrm{E} \propto \mathrm{T}\) Since, the temperature is same for both oxygen and nitrogen therefore, \(\mathrm{E}_{\mathrm{O}_{2}}=\mathrm{E}_{\mathrm{N}_{2}}\) \(\therefore \mathrm{E}_{\mathrm{N}_{2}}=0.048 \mathrm{eV}\)

Hence, the correct answer is option: 'C'.

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