The rms speed of the molecules of gas in a vessel is 400 m/s. If half of the gas leaks out at constant temperature, the rms speed of the remaining molecules will be :

800 m/s 400\(\sqrt{2}\) m/s 400 m/s 200 m/s

400 m/s

Root mean square velocity does not depend upon the quantity of gas. For a given gas and at constant temperature, it always remains the same.