The correct option is D 8
We know,
Specific gas constant, Rspecific=RM
where M is molar mass.
⇒Rspecific (A)Rspecific (B)=MBMA=116
From Graham's law of effusion,
rArB=√MBMA
where rA and rB are the rate of effusion for gas A and B.
∴rArB=√116=14
Also
⇒VAtVBt=rArB=14
Where
VA and VB are the volume of gas effused and t is the time taken for effusion.
We know,
For same pressure and temperature,
V∝n (no. of moles)
⇒nAnB=rArB=14
⇒nB=4nA=4×2=8 moles