The rms speed of A. 125 ms^–1

B. 2000 ms^–1

C. 8000 ms^–1

D. 31 ms^–1

Root mean square velocity of gas is given as

v_rms =

where R=gas constant whose value is 8.31 J/mol K

T=temperature of gas

M= molar mass of molecule of gas

rms speed of oxygen = …(i)

rms speed of hydrogen= …(ii)

Given:

v_rms(o)=500m/s

and we know molar mass of oxygen =M(o)=32

molar mass of hydrogen=M(H)=2

Diving equation (i) and (ii) we get

Since speed of both gases must be calculated at same temperature this equation will reduce to

m/s ()

Root mean square velocity of hydrogen is 2000m/s.