Answer /-
A.0.0931 mol
from ideal gas equation ,
We have ,
PV = nRT
Where P stands where pressure of gas.
We know that pressure of gas at STP = 1 atm
V stands for volume of gas , given Volume is 2.085 L
R stands for gas constant , R = 0.0821
And T stands for absolute temperature and measured in kelvin,T=273K
Now ,
PV = nRT
n = PV/RT
Refer attachment for working
