The tank with a volume of 10 m³ is filled with air. Initially, there is air in the tank at a pressure of 1 atm and a temperature of 23 C. While the tank was filling, it was determined that the pressure value (measured value) was 7 bar within 15 minutes with the pressure gauge placed on it. The barometric pressure is 760 mmHg and the temperature remains constant during filling.

a) Derive the relationship of the moles of air in the tank with time.

b) Find the moles of oxygen in the tank after 35 minutes.

c) The tank is equipped with a safety valve that opens at 120 bar to prevent explosion. Calculate the time it takes for the safety valve to open.

(Answers: b) 1.5 kmol, c) 4.2 hours)