NEET-XII-Physics

24: Kinetic Theory of Gases

with Solutions - page 4
Qstn# iv-12 Prvs-QstnNext-Qstn
  • #12
    Find the rms speed of hydrogen molecules in a sample of hydrogen gas at 300 K. Find the temperature at which the rms speed is double the speed calculated in the previous part.
    Ans : Here,
    Temperature of hydrogen gas, T = 300 K
    Molar mass of hydrogen, M​0 = 2 g/mol=0.002 kg /mol
    We know,
    `` C=\sqrt{\frac{3RT}{{M}_{0}}}``
    `` \Rightarrow C=\sqrt{\frac{3\times 8.3\times 300}{0.002}}``
    `` \Rightarrow C=1932.6{\,\mathrm{\,ms\,}}^{-1}``
    In the second case, let the required temperature be T.
    ​Applying the same formula, we get
    `` \sqrt{\frac{3\times 8.3T}{0.002}}=2\times 1932.6``
    `` \Rightarrow T=1200\,\mathrm{\,K\,}``
    `` ``