5.15 Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm3 at 27°C. R = 0.083 bar dm3 K1 mol1.

Given,
Mass of dioxide (O2) = 8g
Thus, number of moles of O2=832=0.25mole
Mass of dihydrogen (H2) = 4 g
Thus, the number of moles of H2=42=2mole
Therefore, total number of moles in the mixture = 0.25 + 2 = 2.25 mole
Given, V = 1dm3n=2.25mol
R = 0.083 bar dm3K-1mol-1
T = 27°C = 300 K
Total pressure (p) can be calculated as: pV
= nRT
p=nRTV
=225×0.083×3001
=56.025bar
Hence, the total pressure of the mixture is 56.025 bar.