question_answer 9)

                At what temperature is the root mean square speed of an atom in an argon gas cylinder equal to the r.m.s. speed of a helium gas atom at - 20°C ? (Atomic mass of Ar =  u, of He = u).         

Answer:

Let C and C' be the r.m.s. velocity of argon and a helium gas atoms at temperature TK and T' K respectively. Here,                     Now,     and                 Since,    therefore Or