Q 11-12-075JEE MainJEE Main 2023 (12 Apr, Shift 1)Easy
If the r.m.s. speed of chlorine molecule is $490\ \text{m s}^{-1}$ at $27^\circ\text{C}$, the r.m.s. speed of argon molecules at the same temperature will be (Atomic mass of argon $=39.9$ u, molecular mass of chlorine $=70.9$ u)
Answer: (B) $651.7\ \text{m s}^{-1}$
$v\propto\dfrac1{\sqrt M}$: $v_{Ar}=490\sqrt{\dfrac{70.9}{39.9}}=490\times1.333\approx652\ \text{m s}^{-1}$.
Solution by Sreeraj P, M.Sc Physics