At room temperature, the rms speed of the molecules of certain diatomic gas is found to be 1930 m/s. The gas is :

H2 F2 O2 Cl2

H2

Root mean square velocity : \(v_{rms} = \sqrt{\frac{3RT}{M}}\) = 1930 m/s M = \(\frac{3RT}{1930^2} = \frac{3*8.31*300}{1930^2}\) = 2 x 10-3 kg M = 2 g