Question

What is the volume of 2g $O_2$ at 0 degree centigrade and 760 mm pressure of Hg?

Answer 1

$\frac{T_1}{T_2}=\frac{P_1}{P_2}{P}_2=P_1\frac{T_2}{T_1}$
If the container is cylinder the volume is always constant. Only P and T change.