Which of the following formula is used to calculate compressibility factor?

Calculate the volume of gas at 1.25 atmosphere, if volume occupied by gas at 1 atmosphere and at same temperature is 25 mL .

Which of the following graphs explains Boyle's law?

How many moles of dioxygen are present in $8.314 \times 10^{-3} \mathrm{~m}^3$ of it at 318 K having pressure $3.18 \times 10^5 \mathrm{Nm}^{-2} ?\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$