Dear student,

At NTP, pressure is 1atm. Now, rms velocity of H2 is 2000m/s

Let v1 = rms velocity of H2 and v2 be the rms velocity of O2.

Rms velocity = (3RT/M)^1/2 { M = molar mass }

Let M1=molar mass ofH2 = 2g /mol

and that of oxygen(O2) = M2 = 32g/moL

So, v1 = (3RT/2)^1/2

And v2 = (3RT/32)^1/2

so dividingv1 by v2

2000 / v2 = (16)^1/2

So, v2 = 500 m/s

So, Rms velocity of oxygen is 500m/s.