wiz-icon
MyQuestionIcon
MyQuestionIcon
173
You visited us 173 times! Enjoying our articles? Unlock Full Access!
Question

The equilibrium constant KP for the reaction
N2O4(g)2NO2 (g) is 4.5.
What would be the average molar mass (in g⁄mol) of an equilibrium mixture of N2O4 and NO2 formed by the dissociation of pure N2O4 at a total pressure of 2 atm?

A
69
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
57.5
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
80.5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
85.5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 57.5
Let initial mole of N2O4 (g) be 1

N2O4(g)2NO2(g)
initial moles 1 0
atequilibrium 1α 2α
total number of moles at equilibrium = 1+α

PN2O4=1α1+α×P
PNO2=2α1+α×P

Hence, Kp=P2NO2PN2O4=4α2(1α2)×P
4.5=4α2(1α2)×2
α=0.6

Mole fraction of N2O4,
χN2O4=1α1+α=0.25

So average molar mass of mixture,
=0.25×92+0.75×46=57.5

χNO2=10.25=0.75

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Equilibrium Constants
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon