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) H_{2}

(b) F_{2}

(c) O_{2}

(d) CI_{2}

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 H_{2}