Question

At STP the order of mean square velocity of molecules of H2 , N2 , O2 and HBr is -

(A) H2 > N2 > O2 > HBr

(B) HBr > O2 > N2 > H2

(C) HBr > H2 > O2 > N2

(D) N2 > O2 > H2 > HBr

Answer 1

Correct Answer is: (A) H2 > N2 > O2 > HBr

Vrms ∝ 1/√M 'M' is Molecular wt.

order of M.wt. = H2 < N2< O2 < HBr

∴ order of Vrms = H2 > N2 > O2 > HBr.