The rms speed of molecules in hydrogen gas is vrms =√
3kBT
m
where, m= mass of hydrogen, kB= Boltzmann's constant and T= temperature in kelvin. ∴vrms ∝√T Initial temperature, T1=(27+273K)=300K If initial rms speed be v1. Final rms speed, v2=2v1 at temperature T2. ∴