NEET-XII-Physics

24: Kinetic Theory of Gases

with Solutions - page 2
Qstn# ii-11 Prvs-QstnNext-Qstn
  • #11
    The rms speed of oxygen molecules in a gas is v. If the temperature is doubled and the oxygen molecules dissociate into oxygen atoms, the rms speed will become
    (a) v
    (b)
    v2
    (c) 2v
    (d) 4v.
    digAnsr:   c
    Ans : `` \,\mathrm{\,Given\,}:\,\mathrm{\,v\,}=\sqrt{\frac{3\,\mathrm{\,RT\,}}{32}}``
    `` \,\mathrm{\,Suppose\,}\,\mathrm{\,the\,}\,\mathrm{\,new\,}\,\mathrm{\,rms\,}\,\mathrm{\,speed\,}\,\mathrm{\,be\,}\,\mathrm{\,v\,}\text{'}.``
    `` \,\mathrm{\,Molecule\,}\,\mathrm{\,dissociate\,},M=16``
    `` ``
    `` v\text{'}=\sqrt{\frac{3R\left(2T\right)}{16}}``
    `` =\sqrt{\frac{3R\left(4T\right)}{32}}``
    `` =2\sqrt{\frac{3RT}{32}}=2v``
    Thus,
    (c) is the correct answer.