[tex]From\ Ideal\ Gas\ Law:\\\\PV=nRT\\\\
P-pressure\\V-volume\\n-number\ of\ moles\\R- universal\ gas\ constant\\T-absolute\ tmeperature\\\\
R=\ 8,3145J/ mol\ K\\P=0,91atm\\
n=1,6moles\\T=25c\\\\
Converting\ units:\\\\
1atm=101,3kPa=101,3*10^3\\
0,91atm=0,91*101,3*10^3=92,183*10^3Pa\\T=25c=273+25=298K\\\\
V=\frac{nRT}{P}=\frac{1,6*8,3145*298}{92183}=0,043m^3=43liters\\\\Answer\ is\ 43\ liters.[/tex]