The volume of an automobile air bag was 66.8 l when inflated at 25 °c with 77.8 g of nitrogen gas. what was the pressure in the bag in kpa

For this question we can use the ideal gas equation,

PV = nRT

P - pressure

V - volume - 66.8 / 1000 m³

n - number of moles - 77.8 g / 28 g/mol = 2.77 mol

R - universal gas constant - 8.314 Jmol⁻¹K⁻¹

T - 25 °C + 273 = 298 K

substituting these values in the equation

P x 0.0668 m³ = 2.77 mol x 8.314 Jmol⁻¹K⁻¹ x 298 K

P = 102.7 kPa