Question

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. $Cl_{2}$

Answer 1

Answer: (A)

$H_{2}$

Answer 2

$V_{rms} = \sqrt{\frac{3RT}{M}}$

$\therefore$ $M = \frac{3RT}{{V_{rms}}^{2}} = \frac{3x8.31x300}{(1930)^{2}} = 2.0078x10^{- 3}kg = 2.00gm$

It is molecular weight of hydrogen $(H_{2})$.