Question

Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessels of 1 dm³ at 27°C. R = 0.083 bar dm³ K^-1 mol^-1.

Answer 1

Mass of oxygen = 8 g

Mass of hydrogen = 4 g

Molar mass of oxygen = 32 g/mol

Molar mass of hydrogen = 2 g/mol

amount of oxygen = {8 g}/{32 g/mol}

= 0.25 mol.

Amount of hydrogen = {4 g}/{2 g/mol}

= 2 mol

From the gas equation

pV = nRT

p x 1 dm³ = (0.25 mol + 2 mol) x 0.083 bar dm³ K^-1 mol^-1 x 300 K

or, p = 56.025 bar