Question

A 500 mL glass flask is filled at 298 K and 1 atm, pressure with three diatomic gases X, Y and Z. The initial volume ratio of the gases before mixing was 5:3:1. The density of the heaviest gas in the mixture is not more than 25 times that of the lightest gas. When the mixture was heated, vigorous reactions take place between X and Y and X and Z in which all the three gases were completely used up.

The gases X, Y, Z respectively are 

(A) H_2, O₂, N₂ 

(B) H₂, O₂, Cl₂ 

(C) H₂, F₂, O₂ 

(D) O₂, H₂, F₂

Answer 1

Correct answer is (C) H₂, F₂, O₂

According to given data.

Mole ratio of gas x,y,z are 5 : 3 : 1

→As given in the question that the density of heaviest gas in the mixture is not more then 25 times that of lightest gas. 

Hence gas mix should be H₂, F₂, O₂