Question

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

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Root means square velocity ${\nu }_{rms}=\sqrt{\frac{3RT}{M}}=1930m/s$ (given)
$\therefore M=\frac{3RT}{(1930{)}^2}=\frac{3\times 8.31\times 300}{1930\times 1930}=2\times {10}^{-3}kg=2gm$ i.e. the gas is hydrogen