we can use the ideal gas law equation to find the volume occupied by the gas
PV = nRT
where
P - pressure - 1.33 atm x 101 325 Pa/atm = 134 762 Pa
V - volume
n - number of moles - 18.0 g / 4 g/mol = 4.5 mol
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature in Kelvin - 29 °C + 273 = 302 K
substituting these values in the equation
134 762 Pa x V = 4.5 mol x 8.314 Jmol⁻¹K⁻¹ x 302 K
V = 83.8 L
volume occupied by He is 83.8 L
