Calculate p_text(O₂)
From the Ideal Gas Law,
pV = nRT = (m/M)RT
p = (mRT)/(MV) = (8 color(red)(cancel(color(black)("g"))) × "0.083 14 bar"·color(red)(cancel(color(black)("L·K"^"-1""mol"^"-1"))) × 273.15 color(red)(cancel(color(black)("K"))))/(32.00 color(red)(cancel(color(black)("g·mol"^"-1"))) × 5 color(red)(cancel(color(black)("L")))) = "1.1 bar"
Calculate p_text(N₂)
STP is defined as and 0 °C and 1 bar.
Since the temperature does not change, we can use Boyle's Law to calculate the pressure of the nitrogen.
p_1V_1 = p_2V_2
p_2 = p_1 × V_1/V_2 = "1 bar" × (0.224 color(red)(cancel(color(black)("L"))))/(5 color(red)(cancel(color(black)("L")))) = "0.045 bar"
Calculate p_text(tot)
p_text(tot) = p_text(O₂) + p_text(N₂) = "(1.1 + 0.045) bar= 1.2 bar"
