A tank volume of 40 liters containing 2.5 kg of oxygen gas at a pressure of 10 atm . How much air should be included in the tank so that the pressure to 15 atm ?
PV = nRT
P = 10
V = 40
n = 2,500/32 = ?
R = 0.08206
T = ?
Then PV = nRT
P = 15
V = 40
n = ?
R = see above
T = from above.
Solve for n, then n = grams/molar mass. You know n and molar mass, solve for grams O2 needed.