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Grade 11Physical Chemistry

One litre of a gaseous mixture of two gases effuses in 311 seconds while 2 liters of oxygen takes 20 minutes. The vapor density of gaseous mixture containing CH4 and H2 is:
(A) 4
(B) 4.3
(C) 3.4
(D) 5

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Profile image of Rohit Singh
6 Years agoGrade 11
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1 Answer

Profile image of Vikas TU
6 Years ago
Acc to Grams law 
r1/r2 = sqrt (M2/M1)
V1/t1 / V2/t2 = sqrt (M2/M1)
puting the values given in question
sqrt(32/M2) = [1*20 *60/ 311*2]
32/M2 = 7.44 
M2 = 4.30 
2* Vapour density = Molecular mass 
Vapour density = molecular mss /2 
==> 4.30 / 2 = 2/15  
Hope this helps