# What is the volume (in liters) of 2.5 moles of oxygen gas measured at 250C and a pressure of 104.5 kpa?

$V = \frac{n R T}{P}$ $\cong$ $100 \cdot L$
Of course you must choose the appropriate Gas constant. Here it is $8.314 \cdot L \cdot k P a \cdot {K}^{-} 1 \cdot m o {l}^{-} 1$.
$\text{Volume}$ $= \frac{2.5 \cdot \cancel{m o l} \times 8.314 \cdot L \cdot \cancel{k P a} \cdot \cancel{{K}^{-} 1} \cdot \cancel{m o {l}^{-} 1} \times 523 \cdot \cancel{K}}{104.5 \cdot \cancel{k P a}}$
$=$ ??L