A 12-m3 oxygen tank is at 17°C and 850 kPa absolute. The valve is opened, and some oxygen is released until the pressure in the tank drops to 650 kPa. Calculate the mass of oxygen that has been released from the tank if the temperature in the tank does not change during the process.

Released oxygen mass: 15.92 kg

Step-by-step explanation:

ideal gas law : P*V=nRT

P:pressure

V:volume

T:temperature

n:number of moles of gas

n [mol] = m [g] / M [u]

m : masa

M: masa molar = 15,999 u (oxygen)

R: ideal gas constant = 8.314472 cm^3 * MPa/K*mol =

grados K = °C + 273.15

P1*V*M/R*T = m1

P2*V*M/R*T = m2

masa released : m1-m2 = (P1-P2) * V*M/R*T

m2-m1 = 200 * 10^-3 MPa * 12 * 10^6 cm^3 * 15.999 u / 8.314472 (cm^3 * MPa/K * mol) * 290. 15 K

m2-m1 = 38 397.6 * 10^3 u*mol / 2412.44 = 15916.5 g = 15.9165 kg