Question

18. A closed vessel contains helium and ozone at a pressure of P atm. The ratio of He and oxygen atoms is 1 : 1. If helium is removed from the vessel, the pressure of the system will reduce to : (A) 0.5 P atm (B) 0.75 P atm (C) 0.25 P atm (D) 0.33 P atm 19 A conotoni 2009 AAA ALLA

JEE/Engineering Exams

Chemistry

Solution

4.5 (2 ratings)

Pozone ( + ) Pitelium ( = ) Patm Pojone ( =P times ) Kozone Prelium ( =P times x ). Helium Wosone ( rightarrow ) Mole fraction of ozone ( x ) Helium ( rightarrow ) Mole froction of Helium Wozone = Moles of OJone Eiven atoms of Ogone toms in Imol of 0,3 Siven atom of Given atoms ( begin{array}{l}text { Osone } text { Atoms in Imole } text { of } 0_{3}end{array}+begin{array}{l}text { of Helium } text { dtoms in I } text { mole of He }end{array} ) [ begin{array}{r} =frac{1}{frac{1}{3 N_{0}}+frac{1}{N_{0}}}=frac{frac{1}{3 N_{0}}}{frac{4}{3 N_{0}}} P_{030 n e}=frac{1}{4} times P=frac{P}{4} text { atm } P_{text {Helivin }}=P-frac{p}{4}=frac{3 p}{4} text { at } m end{array} ] Removal of Helium ( omega_{1} ) yeduce the pressure to ( P / 4 ) etme