Answer:
mass of oxygen gas in Kg = 15.0Kg
Explanation:
Volume of air in the room = 4.0m*5.0m*2.5m = 50m³
volume of oxygen in the room = 21/100 * 50m³ = 10.5m³
using the ideal gas equation; PV=nRT
number of moles of oxygen gas, n = PV/RT
At STP, P = 1atm, V = 10.5m³ = (10.5*1000)dm³ = 10500dm³, R = 0.082 atmdm³K⁻¹mol⁻¹, T = 273K
n = 1 * 10500/ (273 *0.082)
n = 469.04 moles
mass of oxygen gas in Kg = (no of moles * molar mass)/1000
molar mass of oxygen gas = 32g
mass of oxygen gas in Kg = (469.04 * 32)/1000
mass of oxygen gas in Kg = 15.0Kg
