Q: At room temperature, the rms speed of the molecules of a certain diatomic gas is found to be 1930 m/s. the gas is
(a) H2
(b) F2
(c) O2
(d) CI2
Ans: (a)
Sol: $\large v_{rms} = \sqrt{\frac{3RT}{M}}$
$\large 1930 = \sqrt{\frac{3 \times 8.31 \times 10^{3} \times 300}{M}}$
On solving ,
M = 2 g/mol
The gas is H2