At what temperature is the root mean square speed of an atom in an argon gas cylinder equal to the rms speed of a helium gas atom at – 20 °C? (atomic mass of Ar = 39.9 u, of He = 4.0 u)
Let 1 and 2 represent for Argon atom and Helium atom. rms speed of Argon, vrms1=M13RT1 rms speed of Helium, vrms2=M23RT2 According to question, vrms1=vrms2 ∴M13RT1=M23RT2,M1T1=M2T2 or T1=M2T2×M1=4253×39.9=2.52×103K
